# 🚀 Austrix Advisory

# Q. Fintech wealth advisory comes under which domain ?

You should say your **Fintech wealth advisory platform** comes under the **Financial Services Domain**, specifically under:

* **Fintech (Financial Technology)**
    
* **Wealth Management / Investment Advisory**
    
* **Banking, Financial Services, and Insurance (BFSI) Domain**
    

👉 In interviews, the safest and most professional way to phrase it:  
**“I’ve been working in the Fintech domain, more specifically in the wealth management and financial advisory sector, which falls under the BFSI domain.”**

## Q. How would you answer questions about the tools you use in your fintech wealth advisory and how you manage them? How many accounts do you have, and what about VPS and subnets? Are these client-hosted or vendor-hosted? Since I'm in India, how do you communicate everything? Provide these questions and answers in an interview-style format.

Got it! Here’s a **ready-to-use interview answer set** for questions about your fintech wealth advisory platform, infrastructure, accounts, networking, tools, hosting, and communication—crafted for **MAANG/product company-style interviews**. Answers assume your experience in India and AWS-based deployments.

---

## 🎯 Interview Questions & Answers

---

### **Q1. What tools do you use in your fintech wealth advisory platform?**

**Answer:**  
We use a combination of **cloud, DevOps, security, monitoring, and CI/CD tools**:

* **Cloud & Infrastructure:** AWS (EKS, RDS, S3, EC2, Lambda, VPC, Route53).
    
* **IaC & Automation:** Terraform, CloudFormation, Ansible.
    
* **CI/CD Pipelines:** Jenkins, GitHub Actions, Azure DevOps.
    
* **Containerization & Orchestration:** Docker, Kubernetes (EKS).
    
* **Monitoring & Observability:** Prometheus, Grafana, AWS CloudWatch, X-Ray.
    
* **Security & Compliance:** KMS, GuardDuty, Security Hub, Inspector, Macie, Terrascan, Checkov, Snyk, Scout.
    
* **Secrets & Configuration:** AWS Secrets Manager, Parameter Store.
    

These tools help us ensure **secure, compliant, scalable, and automated deployments** across multiple microservices.

---

### **Q2. How do you manage these tools?**

**Answer:**  
We follow a **centralized management and automation strategy**:

* **IaC & GitOps:** Terraform and Helm charts define all infrastructure, deployed via CI/CD pipelines.
    
* **Monitoring & Alerts:** CloudWatch + Grafana dashboards trigger automated alerts to Slack and Ops teams.
    
* **Security & Compliance:** Security Hub aggregates findings from GuardDuty, Inspector, Macie, and other scanners.
    
* **Secrets Management:** Secrets Manager stores credentials, rotated automatically and accessed via IAM roles.
    
* **Auditing:** CloudTrail logs all API actions for accountability and compliance.
    

We maintain **documentation and runbooks** for every tool to ensure smooth onboarding, troubleshooting, and compliance audits.

---

### **Q3. How many AWS accounts do you have and why?**

**Answer:**  
We use a **multi-account strategy** for security, isolation, and compliance:

* **Production:** 1 account (AU primary region).
    
* **Disaster Recovery:** 1 account (SG DR region).
    
* **Development & Testing:** 2–3 accounts for dev, QA, staging.
    
* **Shared Services:** 1 account for monitoring, CI/CD, and central security services.
    

This approach allows **isolation between environments**, easier **IAM & billing management**, and **cross-account security control** via IAM roles and Security Hub.

---

### **Q4. How do you manage networking—VPCs, subnets, etc.?**

**Answer:**  
We follow **best practices for high availability and security**:

* **VPCs:** Separate VPC per environment (prod, dev, DR).
    
* **Subnets:** 3 private + 1 public subnet per AZ (for load balancers, NAT gateways, and worker nodes).
    
* **Multi-AZ:** EKS nodes, RDS, and S3 endpoints deployed across 2–3 AZs in AU and SG.
    
* **Security:** Network policies in Kubernetes + security groups + NACLs for fine-grained access.
    
* **Connectivity:** VPC Peering & Transit Gateway connect shared services and DR.
    

This ensures **resilience, isolation, and zero downtime** even during maintenance or regional failures.

---

### **Q5. Is the platform client-hosted or vendor-hosted?**

**Answer:**  
The platform is **vendor-hosted on AWS**, giving us:

* **Scalability:** Automatically scale EC2/EKS nodes based on demand.
    
* **Global DR:** Secondary region (SG) for disaster recovery.
    
* **Compliance:** AWS certifications help meet PCI-DSS, SOC2, and GDPR requirements.
    
* **Operational efficiency:** Fully managed services reduce operational overhead.
    

---

### **Q6. How do you communicate and coordinate from India?**

**Answer:**

* **Daily Standups:** We use Zoom/Teams for daily scrum calls.
    
* **Ticketing & Tracking:** Jira manages all deployment, security, and configuration tasks.
    
* **Alerts & Notifications:** Slack channels integrate CloudWatch, Security Hub, and CI/CD pipelines.
    
* **Documentation:** Confluence and runbooks document architecture, policies, and troubleshooting steps.
    
* **Cross-team Coordination:** Product, Dev, and Ops teams communicate via scheduled sync meetings and on-demand channels for incident response.
    

---

### **Q7. How do you handle backups, disaster recovery, and zero downtime?**

**Answer:**

* **Backups:** RDS snapshots, EBS volumes, and S3 versioning with automated schedules.
    
* **DR Strategy:** AU primary → SG DR, using cross-region snapshot replication.
    
* **Zero Downtime:** Blue/green deployments for EKS, multi-AZ RDS, rolling updates, and automated health checks.
    
* **Monitoring:** CloudWatch + Prometheus + custom scripts to verify backups and failover readiness.
    

---

### **Q8. How do you secure your environments?**

**Answer:**

* **KMS:** Encrypt all sensitive data at rest.
    
* **IAM:** Least privilege access with service-specific roles.
    
* **Security Tools:** GuardDuty, Security Hub, Inspector, Macie for threat detection.
    
* **CI/CD Security:** Terrascan, Checkov, Snyk, and Scout for IaC and container scanning.
    
* **Audit:** CloudTrail + Security Hub ensures all activities are logged for compliance.
    

---

✅ **Summary Tip for Interviews:**

* Always mention **multi-account isolation, AU/SG DR, encryption with KMS, monitoring, automation, and compliance**.
    
* Tie your answers to **business value**, e.g., protecting customer PII, ensuring regulatory compliance, and minimizing downtime.
    
* Keep answers concise but **technical enough to show expertise**.
    

---

## Q. How many repo do you have consider IAC-terraform/ Ansible-config ansible playbooks/CI with source code /CD with helm and k8s/ Application code with each microservice in folder and Branches inside it for Each env like `dev/qa/stage` or `UAT/ prod` and `DR` depending on this give answer how you would answer and some follow-up questions ?

Perfect! Let’s structure a **ready-to-use interview answer** about **repo structure, branches, and environment management** for your fintech wealth advisory platform, with follow-up questions and answers.

---

## 🎯 Interview Question & Answer

### **Q1. How many repos do you have and how are they organized?**

**Answer:**  
We maintain a **modular Git repository strategy** to isolate responsibilities, simplify CI/CD, and manage multiple environments effectively:

1. **Infrastructure as Code (IaC):**
    
    * **Repo:** `infra-terraform`
        
    * Contains Terraform modules for VPCs, subnets, EKS clusters, RDS, S3, security policies.
        
    * **Branches:** `dev`, `qa`, `stage` (or UAT), `prod`, `dr`.
        
2. **Configuration Management:**
    
    * **Repo:** `ansible-config`
        
    * Contains playbooks, roles, and inventories for EC2/EKS configuration, security hardening, and app setup.
        
    * Branches follow environments: `dev`, `qa`, `stage`, `prod`, `dr`.
        
3. **CI Pipelines:**
    
    * **Repo:** `ci-pipelines`
        
    * Jenkins/GitHub Actions pipeline scripts for build, test, and security scans.
        
4. **CD Pipelines & Kubernetes:**
    
    * **Repo:** `cd-helm-k8s`
        
    * Helm charts for deploying microservices to EKS.
        
    * Environment-specific values stored in `values-dev.yaml`, `values-qa.yaml`, `values-prod.yaml`.
        
5. **Application Code:**
    
    * **Repo:** `microservices`
        
    * Each microservice in a separate folder (e.g., `auth-service/`, `payments-service/`, `transactions-service/`).
        
    * Branches per environment: `dev`, `qa`, `stage`, `prod`, `dr`.
        

**Branch Strategy:**

* `dev` → active development and feature testing.
    
* `qa` → quality assurance and integration testing.
    
* `stage` / `uat` → pre-production validation.
    
* `prod` → production deployments.
    
* `dr` → disaster recovery environment.
    

**Benefits:**

* Clear separation of code and environments.
    
* CI/CD pipelines can trigger environment-specific branches automatically.
    
* Easier rollback and version control per environment.
    
* DR environment stays in sync with prod without affecting other environments.
    

---

### **Q2. Follow-Up Questions & Answers**

**Q2a. How do you handle CI/CD for multiple branches and environments?**  
**Answer:**

* Jenkins / GitHub Actions pipelines are **branch-aware**:
    
    * Merge to `dev` → triggers build + unit test + Dev deployment.
        
    * Merge to `qa` → triggers integration tests + QA environment deployment.
        
    * Merge to `prod` → triggers blue/green or rolling deployment on EKS.
        
* Helm charts and Terraform modules use **environment-specific variables**.
    

---

**Q2b. How do you manage secrets across multiple environments?**  
**Answer:**

* Use **AWS Secrets Manager** or Parameter Store per environment.
    
* CI/CD fetches secrets dynamically at runtime using IAM roles.
    
* No secrets stored in repos or Helm charts.
    

---

**Q2c. How do you maintain consistency between prod and DR environments?**  
**Answer:**

* DR branch (`dr`) mirrors `prod` branch.
    
* Terraform modules and Helm charts use the same IaC and values files with DR-specific overrides.
    
* Automated weekly sync checks ensure infrastructure parity.
    
* Regular DR drills verify backup and restore procedures.
    

---

**Q2d. How do you handle microservice dependencies during deployment?**  
**Answer:**

* Helm charts define **dependencies** using `requirements.yaml`.
    
* CI/CD pipeline orchestrates **sequential deployments**:
    
    1. Core services (auth, user profile)
        
    2. Transaction/payment services
        
    3. Analytics/reporting
        
* Canary or blue/green deployment reduces downtime.
    

---

**Q2e. How do you handle branch conflicts for multiple microservices?**  
**Answer:**

* Each microservice is in a **separate folder/repo**, reducing conflicts.
    
* Feature branches for active development → merge to `dev`.
    
* CI/CD tests integration before QA merge.
    
* Pull requests are reviewed by **service owners**.
    

---

**Q2f. How do you ensure DR environment is deployable at any time?**  
**Answer:**

* DR branch contains latest prod-ready Helm charts and Terraform code.
    
* Automated pipelines deploy DR with **infrastructure and microservice parity**.
    
* Snapshot backups for RDS/S3 and multi-region KMS keys ensure encrypted recovery.
    

---

**Q2g. How many repos do you monitor actively?**  
**Answer:**

* **5 main repos**: `infra-terraform`, `ansible-config`, `ci-pipelines`, `cd-helm-k8s`, `microservices`.
    
* Optional additional repos for: documentation, shared libraries, monitoring scripts.
    
* Each repo is **branch-aware**, and we have **multi-account monitoring** for AU prod and SG DR.
    

---

### ✅ Key Points to Highlight in Interviews

* Branch-per-environment strategy (`dev`, `qa`, `stage/uat`, `prod`, `dr`).
    
* Repo-per-responsibility: IaC, config, CI, CD, microservices.
    
* Automated CI/CD triggers per branch.
    
* Secrets management & environment parity.
    
* DR readiness and multi-region support (AU/SG).
    
* Blue/green or rolling deployments ensure zero downtime.
    

---

### **Q1. How many repos do you have and how are they organized?**

**Answer:**  
Currently, our codebase is **not very large**, but we have adopted a **modular repository strategy** to ensure clarity, maintainability, and future scalability. This makes it easier to **enhance the platform or add new features** if the client requests updates.

Our repo structure is:

1. **Infrastructure as Code (IaC)** – `infra-terraform`
    
    * Terraform modules for VPCs, subnets, EKS clusters, RDS, S3, security policies.
        
    * Branches: `dev`, `qa`, `stage/uat`, `prod`, `dr`.
        
2. **Configuration Management** – `ansible-config`
    
    * Ansible playbooks and roles for EC2/EKS configuration and app setup.
        
    * Branches follow environments.
        
3. **CI Pipelines** – `ci-pipelines`
    
    * Jenkins/GitHub Actions pipelines for builds, tests, and security scans.
        
4. **CD Pipelines & Kubernetes** – `cd-helm-k8s`
    
    * Helm charts and environment-specific values for deploying microservices to EKS.
        
5. **Application Code** – `microservices`
    
    * Each microservice in its own folder (e.g., `auth-service/`, `payments-service/`).
        
    * Branches per environment: `dev`, `qa`, `stage/uat`, `prod`, `dr`.
        

**Branch Strategy:**

* `dev` → active development
    
* `qa` → integration and testing
    
* `stage/uat` → pre-production validation
    
* `prod` → production
    
* `dr` → disaster recovery
    

**Benefits:**

* Clear separation of responsibilities even with a small codebase.
    
* Makes future **enhancements or client-requested features easier to implement** without disrupting other services.
    
* Environment-specific branches allow safe CI/CD deployments and rollback if needed.
    
* DR branch ensures **production parity and readiness** for disaster recovery.
    

---

# **Q: How do you deploy to clusters and manage different QA tests like functional, integration, regression?**

**Answer:**

Yes, we maintain **separate clusters per environment**:

* **dev** – developers deploy and test new features.
    
* **qa** – used for functional, integration, and regression testing.
    
* **stage/uat** – pre-production validation.
    
* **prod** – live production.
    
* **dr** – disaster recovery, mirrors production.
    

**Deployment Strategy:**

1. **Namespaces for Service Isolation:**
    
    * Within each cluster (especially QA and dev), each microservice is deployed in its **own namespace**:
        
        ```plaintext
        auth-service-qa
        payments-service-qa
        transactions-service-qa
        ```
        
    * This allows multiple services to coexist without port or resource conflicts and isolates teams.
        
2. **QA Testing Segregation:**
    
    * QA team performs **functional, integration, and regression testing** on the same cluster but in **different namespaces or separate ingress paths**.
        
    * Example:
        
        ```plaintext
        Functional tests → functional.auth-service-qa.aadiitya.life
        Integration tests → integration.auth-service-qa.aadiitya.life
        Regression tests → regression.auth-service-qa.aadiitya.life
        ```
        
    * Kubernetes **Ingress** or **Service URLs** are configured per namespace or per testing type.
        
3. **Deployment Automation:**
    
    * CI/CD pipeline (Jenkins / GitHub Actions) deploys the correct **Helm chart values** per namespace/testing type.
        
    * Pipelines ensure **idempotent deployments**, rollback on failures, and apply environment-specific configs.
        
4. **Shared Resources & Data:**
    
    * Common test databases or staging S3 buckets are **namespace-scoped** or cloned per test type to avoid conflicts.
        
    * Secrets are injected using **namespace-specific Kubernetes secrets**.
        
5. **Benefits:**
    
    * **Parallel testing:** Functional, integration, and regression tests can run concurrently in the same QA cluster.
        
    * **Isolation:** Issues in one test type don’t affect others.
        
    * **Efficiency:** Avoids spinning up multiple clusters for every QA type, saving cost.
        
    * **Consistency:** Same cluster config ensures testing mimics production.
        

**Example Workflow for QA Deployment:**

1. Developer merges feature to `qa` branch.
    
2. CI/CD pipeline triggers: Helm deploys microservice to `auth-service-qa` namespace.
    
3. Functional testing team accesses [`functional.auth-service-qa.aadiitya.life`](http://functional.auth-service-qa.aadiitya.life).
    
4. Integration tests run in [`integration.auth-service-qa.aadiitya.life`](http://integration.auth-service-qa.aadiitya.life).
    
5. Regression tests run in [`regression.auth-service-qa.aadiitya.life`](http://regression.auth-service-qa.aadiitya.life).
    
6. Findings/bugs are reported via Jira; fixes merged → redeployed to same namespaces.
    

---

**Key Points to Emphasize in Interview:**

* Separate **clusters for major environments**, namespaces for **per-service isolation**.
    
* **Ingress URLs or service endpoints** for different QA test types.
    
* CI/CD pipelines manage **namespace-targeted deployments**.
    
* Enables **parallel testing** and **resource isolation** without spinning up extra clusters.
    
* Maintains **production parity** and ensures **repeatable testing environments**.
    

---

## Q. Ho how you deploy a code from specific folder from repo to that specific namespace ? Give step by step implementation so you give path inside Argo CD and Jenkins pipeline as you said you have different pipelines for each service ?

Perfect! Let’s break this down into a **step-by-step workflow** showing how you deploy code from a **specific folder/repo** to a **specific namespace** in Kubernetes using **Jenkins + Argo CD**, tailored to your fintech microservices setup.

---

## **Scenario:**

* Repo: `microservices`
    
* Folder: `auth-service/`
    
* Environment: `qa`
    
* Namespace: `auth-service-qa`
    
* Deployment tool: Argo CD
    
* CI/CD orchestration: Jenkins
    

---

## **Step 1: Repo Structure**

Example repo:

```plaintext
microservices/
├── auth-service/
│   ├── Dockerfile
│   ├── helm-chart/
│   │   ├── Chart.yaml
│   │   ├── templates/
│   │   └── values.yaml
│   └── src/
├── payments-service/
│   ├── Dockerfile
│   └── helm-chart/
└── transactions-service/
    ├── Dockerfile
    └── helm-chart/
```

* **Key:** Each microservice has its **own Helm chart** for deployment.
    

---

## **Step 2: Jenkins Pipeline for Auth-Service**

**Pipeline goals:**

1. Build Docker image
    
2. Push to ECR
    
3. Update Helm chart values for QA namespace
    
4. Commit changes (optional) and trigger Argo CD deployment
    

```plaintext
pipeline {
    agent any

    environment {
        ECR_REPO = "123456789012.dkr.ecr.ap-southeast-2.amazonaws.com/auth-service"
        IMAGE_TAG = "${env.BUILD_NUMBER}"
        NAMESPACE = "auth-service-qa"
        HELM_PATH = "auth-service/helm-chart"
    }

    stages {
        stage('Checkout') {
            steps {
                git branch: 'qa', url: 'git@github.com:my-org/microservices.git'
            }
        }

        stage('Build Docker Image') {
            steps {
                dir('auth-service') {
                    sh """
                    docker build -t $ECR_REPO:$IMAGE_TAG .
                    aws ecr get-login-password --region ap-southeast-2 | docker login --username AWS --password-stdin $ECR_REPO
                    docker push $ECR_REPO:$IMAGE_TAG
                    """
                }
            }
        }

        stage('Update Helm Chart') {
            steps {
                dir(HELM_PATH) {
                    sh """
                    helm upgrade --install auth-service . \
                        --namespace $NAMESPACE \
                        --set image.repository=$ECR_REPO \
                        --set image.tag=$IMAGE_TAG \
                        --create-namespace
                    """
                }
            }
        }

        stage('Trigger Argo CD Sync') {
            steps {
                sh """
                argocd app sync auth-service-qa --prune
                argocd app wait auth-service-qa --health
                """
            }
        }
    }
}
```

**Explanation:**

* `git branch: 'qa'` → checkout QA branch of repo.
    
* Docker build/push → pushes microservice image to ECR.
    
* Helm upgrade/install → deploys to **auth-service-qa namespace**.
    
* Argo CD sync → ensures GitOps state matches cluster.
    

---

## **Step 3: Argo CD Application for Namespace**

**Argo CD app YAML example (**`auth-service-qa.yaml`):

```plaintext
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: auth-service-qa
  namespace: argocd
spec:
  project: default
  source:
    repoURL: 'git@github.com:my-org/microservices.git'
    targetRevision: qa
    path: 'auth-service/helm-chart'
  destination:
    server: 'https://kubernetes.default.svc'
    namespace: auth-service-qa
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
```

**Explanation:**

* `path: 'auth-service/helm-chart'` → points Argo CD to **specific folder** in repo.
    
* `targetRevision: qa` → uses the QA branch.
    
* `namespace: auth-service-qa` → deploys to the QA namespace.
    
* `automated sync` ensures GitOps state is always applied.
    

---

## **Step 4: Multiple Microservices / Namespaces**

* Repeat the Jenkins + Argo CD setup for each microservice.
    
* Each service has:
    
    * Its own Helm chart folder
        
    * Dedicated namespace (e.g., `payments-service-qa`)
        
    * Separate Argo CD application for GitOps sync
        

---

## **Step 5: QA Testing Segregation**

* QA team accesses services via **Ingress URLs**:
    
    * [`auth-service-qa.aadiitya.life`](http://auth-service-qa.aadiitya.life) → functional tests
        
    * [`payments-service-qa.aadiitya.life`](http://payments-service-qa.aadiitya.life) → integration tests
        
* Multiple QA tests run in the **same cluster**, isolated per namespace.
    

---

## **Step 6: Benefits**

* Clear **folder → namespace mapping**.
    
* GitOps (Argo CD) ensures cluster matches repo.
    
* CI/CD pipelines deploy per environment safely.
    
* Namespaces isolate **microservices and testing types**.
    
* Future microservices added → only a new folder + namespace + pipeline needed.
    

---

# Q. I said we have diff repo for `CI` i.e. Code and once `CI` finishes execution it will automatically trigger `CD` and deploys to k8s in `dev/qa/stage` only for prod we have manual trigger ?

Perfect! Let’s rephrase and structure the answer **according to your repo strategy**—separate repos for CI and CD, automated deployment for dev/qa/stage, and manual for prod. Here’s a **ready-to-use interview answer**:

---

### **Q: How do you deploy code to different clusters and namespaces?**

**Answer:**

We follow a **modular CI/CD strategy** with **separate repos for code, CI, and CD**:

1. **Repo Structure:**
    
    * `microservices` → application code for each service in separate folders (`auth-service/`, `payments-service/`).
        
    * `ci-pipelines` → Jenkins/GitHub Actions pipelines to build, test, and push Docker images.
        
    * `cd-helm-k8s` → Helm charts and Argo CD configuration for deploying microservices to Kubernetes clusters.
        
2. **CI/CD Flow:**
    
    * Developers commit code to the **feature/dev branch**.
        
    * CI repo pipelines automatically:
        
        * Run unit and integration tests.
            
        * Build Docker images and push to ECR.
            
    * Once CI finishes successfully, it **automatically triggers CD** for **dev, QA, and stage environments**:
        
        * Helm charts in `cd-helm-k8s` deploy the updated images to the **respective namespace** in the cluster.
            
    * **Prod deployment** is **manual**: Only triggered by the release manager after approvals and final testing.
        
3. **Namespace Mapping:**
    
    * Each microservice has its **own namespace** per environment:
        
        ```plaintext
        auth-service-dev
        auth-service-qa
        auth-service-stage
        auth-service-prod
        ```
        
    * This allows isolation of resources and independent testing for functional, integration, and regression scenarios.
        
4. **Argo CD Integration:**
    
    * CD repo is GitOps-driven using Argo CD.
        
    * Each environment has an Argo CD application pointing to the **Helm chart folder** and **environment-specific values**.
        
    * Automated sync applies changes to dev, QA, and stage.
        
    * Manual sync is used for prod to ensure **controlled release**.
        
5. **Benefits:**
    
    * **Separation of concerns**: CI handles build/test; CD handles deployment.
        
    * **Environment isolation** via namespaces.
        
    * **Automated deployment** for non-prod reduces human error.
        
    * **Manual control for prod** ensures safe releases.
        
    * Scales easily for future microservices or additional environments.
        

---

### **Follow-up Questions You Might Get**

**Q1. How do you ensure QA can perform functional, integration, and regression testing in the same cluster?**

* QA namespaces are isolated per microservice and optionally per test type ([`functional.auth-service-qa.aadiitya.life`](http://functional.auth-service-qa.aadiitya.life), [`integration.auth-service-qa.aadiitya.life`](http://integration.auth-service-qa.aadiitya.life)). CI/CD pipelines deploy images to the appropriate namespace so multiple test types can run in parallel without conflict.
    

**Q2. How do you handle rollbacks?**

* Helm keeps **release history per namespace**.
    
* If a deployment fails or test finds issues, we can rollback to a previous image/tag via Helm or Argo CD.
    

**Q3. How do you manage secrets and environment-specific configurations?**

* Secrets are stored in **AWS Secrets Manager** per environment/namespace.
    
* CD pipelines inject the secrets dynamically during deployment; they are never hardcoded in repos.
    

**Q4. How do you deploy new microservices?**

* Add a **new folder in microservices repo**, Helm chart in CD repo, create a namespace per environment, and update Argo CD application.
    
* CI/CD pipelines automatically pick up the new service for dev/qa/stage deployments.
    

---

# Q How do you handle rollback ? with example ?

Here’s a **clear, interview-ready answer** for handling rollbacks in your Kubernetes/CI-CD setup, with an example specific to your fintech wealth advisory platform:

---

### **Q: How do you handle rollbacks?**

**Answer:**

We handle rollbacks at **both CI/CD and Kubernetes levels** using Helm and Argo CD, ensuring minimal downtime and fast recovery.

---

### **1️⃣ Helm Rollback (Namespace-specific)**

* Every microservice is deployed via **Helm charts** into its environment-specific namespace (`auth-service-qa`, `auth-service-dev`, `auth-service-prod`).
    
* Helm keeps a **release history** per namespace.
    
* If a deployment fails or a bug is detected after deployment, we can **rollback to a previous working release** with a single command:
    

```plaintext
# Check release history
helm history auth-service --namespace auth-service-qa

# Rollback to previous version
helm rollback auth-service 2 --namespace auth-service-qa
```

* `2` refers to the previous release version.
    
* This immediately restores the **previous stable image/configuration** without affecting other services or namespaces.
    

---

### **2️⃣ Argo CD Rollback (GitOps Approach)**

* All deployments are GitOps-managed via **Argo CD**.
    
* If a release introduces issues, we can **revert the Git commit** in the CD repo (Helm chart or values file) to the last stable version:
    

```plaintext
# Sync Argo CD application after revert
argocd app sync auth-service-qa --prune
```

* Argo CD applies the previous Helm chart state to the namespace.
    
* This ensures the **cluster state matches the repository**.
    

---

### **3️⃣ CI/CD Rollback Triggers**

* CI pipelines are configured to **tag Docker images with build numbers**.
    
* If a rollback is needed, we can trigger the Helm chart to deploy a **specific previous image tag**:
    

```plaintext
helm upgrade --install auth-service auth-service/helm-chart \
  --namespace auth-service-qa \
  --set image.tag=45  # previous stable build
```

* This allows **fast rollback without rebuilding images**.
    

---

### **4️⃣ Benefits of Our Rollback Strategy**

✅ Namespace-level isolation prevents impact on other services.  
✅ Multiple rollback options: Helm release, Argo CD GitOps, CI image tag.  
✅ Zero-downtime rollback using **rolling updates** in Helm + Kubernetes.  
✅ Ensures production parity with DR clusters, so DR can also be rolled back in sync.

---

### **Example Scenario in QA Environment:**

1. QA team tests a new feature in `auth-service-qa`.
    
2. Deployment introduces a bug in authentication.
    
3. Pipeline or Argo CD triggers rollback to **previous stable release**:
    
    ```plaintext
    helm rollback auth-service 2 --namespace auth-service-qa
    ```
    
4. QA can immediately resume testing without waiting for a new build.
    

---

If you want, I can **also explain rollback in production with zero downtime** using **blue/green or canary deployments**, which is very impressive for interviews.

Do you want me to cover that next?

##### You said:

# Q. so we don’t use commit style here right ? and how its diff with this and which is better approach for our fintech app ?

Exactly! Let me explain the **difference between commit-style (GitOps) rollback vs. Helm/Argo CD release rollback** and which approach fits your **wealth advisory fintech platform**.

---

## **1️⃣ Commit-Style Rollback (GitOps)**

**How it works:**

* In GitOps, your **cluster state is a reflection of the Git repository** (CD repo).
    
* Rollback happens by **reverting the Git commit** that introduced the bad change.
    
* Argo CD or Flux detects the repo change and **syncs the cluster back** to the previous state.
    

**Example:**

```plaintext
# Revert bad commit in CD repo
git revert <commit-hash>
git push origin qa

# Argo CD sync applies previous state
argocd app sync auth-service-qa
```

**Pros:**

* **Full history of changes** in Git.
    
* Enforces **audit/compliance**, ideal for regulated fintech apps.
    
* Guarantees **cluster state matches repository**.
    

**Cons:**

* Requires **Git operations** for rollback (slightly slower).
    
* Not ideal for **emergency quick rollback** unless pipeline is automated.
    

---

## **2️⃣ Helm/Argo CD Release Rollback**

**How it works:**

* Helm keeps **release history per namespace**.
    
* Rollback is done via **Helm rollback command**, optionally via Argo CD UI.
    

**Example:**

```plaintext
helm rollback auth-service 2 --namespace auth-service-qa
```

**Pros:**

* **Instant rollback** without touching Git.
    
* Works even if GitOps repo is behind or has pending commits.
    
* Good for **hotfixes in QA or dev**, faster recovery.
    

**Cons:**

* Less **audit-friendly** than Git revert (need to check Helm history separately).
    
* Manual rollback might cause divergence if Git repo is not updated.
    

---

## **3️⃣ Which is Better for Our Fintech Wealth Advisory Platform?**

| Aspect | Commit-Style (GitOps) | Helm/Release Rollback |
| --- | --- | --- |
| **Speed** | Slower (requires Git revert) | Fast (single command) |
| **Audit & Compliance** | Excellent (Git history) | Moderate (Helm history only) |
| **Use Case** | Production, regulated changes | QA/dev, hotfixes, emergency rollback |
| **Cluster-State Consistency** | Perfect, always matches repo | Needs manual check |

**Our Strategy:**

* **Dev/QA/Stage:** Use **Helm/Release rollback** for speed and agility.
    
* **Prod/DR:** Use **GitOps commit-style rollback** for audit, compliance, and full traceability.
    

**Rationale:**

* Fintech apps require **strict audit and compliance** in production.
    
* Non-prod environments need **rapid testing and rollback** without waiting for Git operations.
    
* This hybrid approach balances **speed, safety, and compliance**.
    

---

# Q So which one is better ?

For your **wealth advisory fintech platform**, the “better” approach depends on **environment and goals**:

---

### **Recommendation:**

* **Dev / QA / Stage:** **Helm/Release rollback**
    
    * **Reason:** Fast, simple, allows rapid iteration and testing.
        
    * Developers and QA can quickly revert a failed deployment without touching Git.
        
* **Production / DR:** **Commit-style GitOps rollback**
    
    * **Reason:** Full audit trail, compliance-friendly, ensures cluster state exactly matches repo.
        
    * Slower than Helm rollback but critical for **regulated fintech environments**.
        

---

✅ **Summary:**

* **Speed-focused rollback:** Helm rollback → good for dev/QA.
    
* **Compliance-focused rollback:** GitOps commit revert → mandatory for prod/DR.
    

**Hybrid approach** gives you **both agility in testing** and **regulatory safety in production**.

---

## Q . So I can say Commit based right ? and for qa/stage and production it gets deployed when we create tag so we use tag rollback version right give example of command right from creating tag and then rolling back ?

Exactly! You **can say “commit/tag-based rollback”** for production and DR, and use **tags for QA/stage/prod deployments**. Here’s how you can explain it clearly in an interview with **step-by-step example**:

---

## **Commit/Tag-Based Deployment & Rollback Workflow**

### **1️⃣ Create a Tag for Deployment**

* When code in a branch (e.g., `qa` or `prod`) is ready to deploy, we **create a Git tag** to mark a release version:
    

```plaintext
# Checkout the branch to deploy
git checkout prod

# Create a version tag (semantic versioning recommended)
git tag -a v1.2.0 -m "Release v1.2.0 for production"

# Push tag to remote
git push origin v1.2.0
```

* This **immutable tag** is what CI/CD and Argo CD pipelines use for deployment.
    

---

### **2️⃣ Deploy Tagged Version Using Argo CD / CI-CD**

* In Argo CD, you can **specify the tag in the application source** (Helm chart values or container image tag).
    

```plaintext
# Example using Helm for deployment
helm upgrade --install auth-service auth-service/helm-chart \
  --namespace auth-service-prod \
  --set image.tag=v1.2.0 \
  --create-namespace
```

* Argo CD sync ensures **cluster matches Git/Helm state** automatically.
    

---

### **3️⃣ Rollback to Previous Tag**

* If a problem occurs, simply **rollback to a previous tag**:
    

```plaintext
# Helm rollback using image tag
helm upgrade --install auth-service auth-service/helm-chart \
  --namespace auth-service-prod \
  --set image.tag=v1.1.5  # previous stable release
```

* Or via **GitOps approach**: revert to the commit that created the previous tag:
    

```plaintext
# Revert Git commit to previous stable release
git checkout prod
git revert <commit-hash-for-v1.2.0>
git push origin prod

# Argo CD sync
argocd app sync auth-service-prod
```

* The cluster now runs the **previous stable version**, ensuring **zero downtime rollback** when used with **rolling updates**.
    

---

### **4️⃣ QA/Stage Deployments**

* QA and Stage also follow **tagged deployments**, so every test environment is versioned:
    

```plaintext
# Deploy to QA using tag
helm upgrade --install auth-service auth-service/helm-chart \
  --namespace auth-service-qa \
  --set image.tag=v1.2.0
```

* If a test fails, rollback is just **another Helm upgrade to the previous tag**, fast and isolated in the QA namespace.
    

---

### **Key Points to Highlight in Interviews**

* Tags give **immutable, traceable versions**.
    
* QA/Stage/Prod use tags → easy rollback and traceability.
    
* GitOps + tags = full audit trail for production.
    
* Helm rollback + tags = fast recovery in QA/dev.
    
* Supports **multi-environment deployments** with the same artifact.
    

---

# Q. Modify anser with as we have an shell cript to update image inside the deployment i.e. helm manifest

Got it! Here’s a **modified interview-ready answer** incorporating your **shell script that updates the image in Helm manifests**, along with the commit/tag-based deployment and rollback workflow:

---

## **Commit/Tag-Based Deployment & Rollback Workflow with Shell Script**

### **1️⃣ Create a Tag for Deployment**

* When code in a branch (e.g., `qa` or `prod`) is ready to deploy, we **create a Git tag**:
    

```plaintext
git checkout prod
git tag -a v1.2.0 -m "Release v1.2.0 for production"
git push origin v1.2.0
```

* Tags are **immutable** and serve as the deployment reference.
    

---

### **2️⃣ CI/CD Updates Helm Manifest Using Shell Script**

* Our CI/CD pipeline has a **shell script** that updates the Docker image tag inside the Helm `values.yaml` or manifest before deployment.
    

**Example shell script (**[`update-helm-image.sh`](http://update-helm-image.sh)):

```plaintext
#!/bin/bash

# Usage: ./update-helm-image.sh <service> <namespace> <image-tag>
SERVICE=$1
NAMESPACE=$2
IMAGE_TAG=$3

HELM_PATH="./$SERVICE/helm-chart"

echo "Updating image tag for $SERVICE to $IMAGE_TAG in namespace $NAMESPACE"
sed -i "s|repository:.*|repository: 123456789012.dkr.ecr.ap-southeast-2.amazonaws.com/$SERVICE|" $HELM_PATH/values.yaml
sed -i "s|tag:.*|tag: $IMAGE_TAG|" $HELM_PATH/values.yaml

echo "Deploying via Helm..."
helm upgrade --install $SERVICE $HELM_PATH \
  --namespace $NAMESPACE \
  --create-namespace
```

* Pipeline calls this script automatically after building and pushing the Docker image.
    

```plaintext
./update-helm-image.sh auth-service auth-service-qa v1.2.0
```

* This ensures **image is updated in Helm chart** before deployment, without manually editing manifests.
    

---

### **3️⃣ Rollback to Previous Tag**

* If QA or production finds an issue, rollback is simple:
    

```plaintext
# Use previous stable tag
./update-helm-image.sh auth-service auth-service-qa v1.1.5
```

* Or, in production with GitOps, revert the Git commit for the Helm values.yaml:
    

```plaintext
git checkout prod
git revert <commit-hash-for-v1.2.0>
git push origin prod
argocd app sync auth-service-prod
```

* Cluster now runs **previous stable version**, maintaining **zero downtime** with rolling updates.
    

---

### **4️⃣ QA/Stage Deployments**

* QA and Stage also follow **tagged deployments**, with **shell script updating Helm manifests** automatically:
    

```plaintext
./update-helm-image.sh payments-service payments-service-stage v1.2.0
```

* Each microservice deployed to **its own namespace** (`auth-service-qa`, `payments-service-stage`) → isolates tests for functional, integration, or regression testing.
    

---

### **5️⃣ Key Points for Interview**

* **Shell script automates image updates** in Helm manifests → reduces human error.
    
* Tags ensure **immutable, traceable releases**.
    
* CI/CD automatically triggers deployment to dev/qa/stage; prod is **manual approval**.
    
* Rollback is simple via **script with previous tag** or **GitOps revert**.
    
* **Namespace isolation** allows multiple test types in QA/stage clusters.
    

---

# Q. You said your primary region is Australia and secondary as Singapore why ? and how you have setup a DR strategy may I know ? and all possible follow-up questions on it

Perfect! Let’s frame a **complete interview-ready explanation** for **multi-region setup, DR strategy, and follow-up questions** specifically for your **wealth advisory fintech platform**.

---

## **Q: Why is our primary region Australia and secondary Singapore?**

**Answer:**

* **Primary region: Australia (ap-southeast-2)**
    
    * Our fintech platform’s **main clients are based in Australia**, so hosting in AU ensures **low latency, high performance, and regulatory compliance**.
        
    * All **production workloads, databases, and critical services** run here.
        
* **Secondary region: Singapore (ap-southeast-1)**
    
    * Acts as **disaster recovery (DR) site**.
        
    * Multi-region setup ensures **high availability** and **business continuity** in case of region-level outages, natural disasters, or AWS service disruptions.
        
    * Singapore is chosen because it is **geographically close to Australia**, minimizing replication lag, and AWS has strong compliance and services there.
        

---

## **Q: How is your DR strategy set up?**

**Answer:**

1. **Infrastructure Replication:**
    
    * **IaC (Terraform) modules** deploy almost identical VPC, subnets, EKS clusters, RDS, and S3 buckets in Singapore.
        
    * Separate accounts for **production (AU)** and **DR (SG)** improve isolation and security.
        
2. **Data Replication:**
    
    * **RDS:** Multi-AZ and **cross-region read replicas** in Singapore.
        
    * **S3:** Cross-region replication (CRR) to replicate backups, documents, and static assets.
        
    * **EFS / EBS snapshots:** Scheduled replication to DR region.
        
3. **Cluster & App Deployment:**
    
    * DR cluster mirrors production cluster **namespaces and Helm charts**.
        
    * **Helm values** are adjusted for DR-specific resources (e.g., smaller instance sizes for cost optimization).
        
4. **Backup & Restore:**
    
    * Automated backups using **Velero** or **AWS Backup**:
        
        * Daily RDS snapshots
            
        * Daily S3 bucket replication
            
        * Weekly cluster state backups
            
    * Snapshots are **encrypted with KMS keys** (AU primary key for prod, SG key for DR).
        
5. **Failover / Recovery:**
    
    * DNS fails over via **Route 53** with health checks.
        
    * Production traffic is switched to SG cluster in case of AU outage.
        
    * Regular **DR drills** verify zero-downtime recovery.
        
6. **Cost Optimization:**
    
    * DR cluster uses **smaller instances** (t3.medium vs m5.large in production) until failover is needed.
        
    * Snapshots are retained based on RPO/RTO requirements and **older backups are automatically deleted** to save cost.
        

---

## **Follow-Up Questions You May Get & Answers**

**Q1. How do you determine which services replicate to DR?**

* Critical core microservices (auth, payments, transactions, user profile) replicate fully.
    
* Internal or non-critical services (analytics, reporting) may use **on-demand deployment** to save cost.
    

**Q2. How often do you backup production data to DR?**

* RDS snapshots: **daily**, with **point-in-time recovery** enabled.
    
* S3: **real-time cross-region replication**.
    
* Cluster state: **weekly Velero backups**, stored in DR S3 bucket.
    

**Q3. How do you ensure DR cluster is ready at any time?**

* DR Helm charts mirror prod charts, using **same IaC modules**.
    
* Automated pipelines deploy latest prod images to DR periodically.
    
* Regular **DR drills** simulate failover.
    

**Q4. How do you manage secrets in DR region?**

* Secrets in DR are stored in **AWS Secrets Manager in SG**, encrypted with **DR-specific KMS key**.
    
* CI/CD pipelines fetch secrets dynamically during failover or routine DR sync.
    

**Q5. How do you handle RTO and RPO?**

* **RPO (Recovery Point Objective):** Max data loss tolerated = 15–30 mins → RDS PITR + CRR ensures this.
    
* **RTO (Recovery Time Objective):** Max downtime tolerated = 1 hour → DR cluster can be promoted and DNS switched quickly.
    

**Q6. How do you handle failback after disaster?**

* After AU region recovers, data is **replicated back from SG** to AU.
    
* Helm charts and pipelines redeploy workloads to primary.
    
* Route53 health checks switch traffic back.
    

**Q7. How do you save cost while keeping DR ready?**

* Smaller instance types in DR cluster (t3.medium).
    
* Snapshots older than retention policy auto-deleted.
    
* Only core services replicate continuously; non-critical services are **deployed on-demand**.
    

**Q8. How do you validate DR readiness?**

* Regular **DR drills**: failover production traffic to DR cluster in SG.
    
* Verify **RDS snapshots**, **S3 replication**, and **cluster health**.
    
* Automated monitoring alerts if replication fails.
    

---