Kubernetes Production Application Platform
Cluster architecture, workloads, networking, scaling and security.
Overview
Architect a production Kubernetes platform covering cluster architecture, workloads, networking, autoscaling and security hardening.
The problem
Run a production-grade application platform on Kubernetes.
Why it matters
This is a real, in-demand scenario: Run a production-grade application platform on Kubernetes.. Teams that can ship and run a kubernetes like this solve an actual business need and are hired for that ability.
What you'll build
- A hardened cluster
- Secure workloads
- Autoscaling
- Network isolation
What you'll learn
- Production Kubernetes
- Hardening
- Scaling
Business problem
Production Kubernetes demands security and reliability, not just working manifests.
Technical problem
Design and operate a secure, resilient production cluster.
When you're done: A working kubernetes project — code committed, tests passing, and documented in your portfolio.
Requirements
User requirements
- Secure workloads
- Autoscale
- Reliable networking
- Upgrades
System requirements
- Cluster
- Workloads
- Network policies
- Scaling
Functional requirements
- Cluster setup
- Secure workloads
- Network policies
- HPA/VPA
- Namespaces
Non-functional requirements
- Secure by default
- Resilient
Technical requirements
- kubeconfig/cluster
- PSP->PSA / pod security
- network policies
Security requirements
- Pod security
- Least privilege
- Secrets
Operational requirements
- Upgrade path documented
Constraints
- Kubernetes
Success criteria
- Workloads hardened
- Scales on load
- Network isolation works
Flows
Request Flow
- 1
Browser
User requests the application over HTTPS.
- 2
CDN / DNS
Edge routes the request to the origin.
- 3
Load Balancer
Distributes traffic across healthy app instances.
- 4
Application
Handles the request, applies business logic.
- 5
Cache
Serves fast reads for hot data.
- 6
Database
Persists data and returns results.
Project Structure
Root of the client application source.
Setup
- 1
Prerequisites
You need the tools required by Kubernetes, kubectl, Helm installed and available on your PATH.
- 2
Clone project
Clone the repository locally.
1. Clone the repositorygit clone <your-repo-url> <project-folder> - 3
Install dependencies
Install the project dependencies.
1. Initialize a Node.js projectLinux / Windowsnpm init -yExpected
Creates a package.json with defaults.
If it fails
command not found: npm
Fix
Install Node.js LTS from the official site, then reopen your terminal.
- 4
Configure environment
Set the environment variables documented for this project. Never commit secrets.
1. Create the environment filecp .env.example .env # then edit values - 5
Start project
Run the development command and confirm it starts.
1. Start the development serverLinux / Windowsnpm run devExpected
Dev server starts; watch terminal for the local URL.
If it fails
Port 3000 is already in use
Fix
Run on another port: npm run dev -- --port 3001, or stop the conflicting process.
- 6
Verify
Open the printed local URL and confirm the primary flow works.
Build Phases
0 of 9 phases complete
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Run
1. Initialize a Node.js projectLinux / Windowsnpm init -yExpected
Creates a package.json with defaults.
If it fails
command not found: npm
Fix
Install Node.js LTS from the official site, then reopen your terminal.
Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Run
1. Install the kubernetes packageLinux / Windowsnpm install kubernetesExpected
Adds kubernetes to node_modules and package.json.
If it fails
npm ERR! network / EACCES
Fix
Check your network or run with sudo on Linux/macOS; on Windows run the terminal as Administrator.
Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Run
1. Start the development serverLinux / Windowsnpm run devExpected
Dev server starts; watch terminal for the local URL.
If it fails
Port 3000 is already in use
Fix
Run on another port: npm run dev -- --port 3001, or stop the conflicting process.
Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Run
1. Build the application for productionLinux / Windowsnpm run buildExpected
A production bundle is emitted to the output directory.
If it fails
Build fails with a type or syntax error
Fix
Read the error message, fix the referenced file, and re-run the build.
Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Objective: Establish the next milestone of the container platform.
What changes: The project advances to the next coherent state, keeping the previous milestones working.
Files touched
Relevant source and configuration files for this milestone.Tasks
- Implement the specific behaviour required for this milestone.
- Verify the previous milestone still works.
Validate: The milestone behaves as expected and does not break existing functionality.
Common mistakes
- • Skipping validation and moving on before confirming the milestone works.
Commands
npm init -yExpected
Creates a package.json with defaults.
If it fails
command not found: npm
Fix
Install Node.js LTS from the official site, then reopen your terminal.
npm install kubernetesExpected
Adds kubernetes to node_modules and package.json.
If it fails
npm ERR! network / EACCES
Fix
Check your network or run with sudo on Linux/macOS; on Windows run the terminal as Administrator.
npm run devExpected
Dev server starts; watch terminal for the local URL.
If it fails
Port 3000 is already in use
Fix
Run on another port: npm run dev -- --port 3001, or stop the conflicting process.
npm run buildExpected
A production bundle is emitted to the output directory.
If it fails
Build fails with a type or syntax error
Fix
Read the error message, fix the referenced file, and re-run the build.
Testing
Unit tests
Core logic and pure functions behave correctly.
npm init -ySuccess: All unit tests pass without errors.
Integration tests
Components integrate correctly with data sources and services.
npm testSuccess: Integration tests pass for the primary flows.
API tests
Endpoints respond to valid and invalid input correctly.
npm testSuccess: API tests cover happy and failure paths.
End-to-end tests
A user can complete the primary journey end to end.
npm run test:e2eSuccess: The main user journey completes successfully.
Security tests
No obvious security regressions are introduced.
npm auditSuccess: No high or critical vulnerabilities.
Debugging & Troubleshooting
ImagePullBackOff
Why: Kubernetes cannot pull the container image.
Check: Inspect the pod events and image name.
kubectl describe pod <pod> | grep -A3 Events
Fix: Fix the image tag, registry auth, or availability.
Prevent: Verify images exist and pull policy is correct.
CrashLoopBackOff
Why: The container keeps starting and crashing.
Check: Read the container logs and previous logs.
kubectl logs <pod> --tail=30 && kubectl logs <pod> --previous
Fix: Fix the application error, missing config, or failing dependency.
Prevent: Add readiness/liveness probes to surface failures early.
Pod stuck Pending
Why: No node can fit the pod — resources, taints, or scheduling.
Check: Inspect events for scheduling failures.
kubectl describe pod <pod> | grep -A3 Events
Fix: Add capacity, remove taints, or reduce resource requests.
Prevent: Request resources your nodes can actually satisfy.
OOMKilled
Why: The container exceeded its memory limit.
Check: Inspect the container state and memory limits.
kubectl describe pod <pod> | grep -i memory
Fix: Raise the limit or reduce the application memory footprint.
Prevent: Set realistic limits and profile memory usage.
Security
Security is treated as a core requirement: input is validated, secrets are protected, and dependencies are kept up to date.
Input validation
Validate and sanitize all user input before use.
Secrets management
Store secrets in environment variables, never in source.
Dependency hygiene
Regularly audit dependencies for known vulnerabilities.
Observability
Logs
- Structured logs for every service
- Centralized log storage with retention
Metrics
- Service, infrastructure and business metrics
- RED and USE coverage
Traces
- Distributed traces across services and infrastructure
Health checks
- Per-service health probes
- External uptime checks
Alerts
- Alerting on SLO burn and critical signals
- On-call escalation paths
Dashboards
- Service, infra and business dashboards
- SLO dashboards
SLIs
- Availability — Proportion of valid requests answered successfully
- Latency — Distribution of response times
- Error rate — Proportion of failed requests
SLOs
- Availability — 99.9% over 30 days
- Latency — P95 under 300ms
Deployment
- 1
Prepare for deployment
Build the production artifact.
1. Build for productionnpm run build - 2
Deploy
Deploy to the project target platform following its documented steps.
1. Deploynpm run deploy # or the platform-specific command - 3
Verify
Confirm the deployed application responds and its health check passes.
1. Check healthcurl -I https://<your-deployed-url>
Documentation
Project Overview
Architect a production Kubernetes platform covering cluster architecture, workloads, networking, autoscaling and security hardening. This is a advanced kubernetes project in the container platform space, built to demonstrate real engineering, not just copied code.
What You Will Build
- A hardened cluster - Secure workloads - Autoscaling - Network isolation
Problem Statement
Production Kubernetes demands security and reliability, not just working manifests. Design and operate a secure, resilient production cluster.
Technology Stack
Kubernetes, kubectl, Helm, Security
Installation
Clone the repository and install dependencies with the documented commands.
Local Development
Run the development command and open the printed local URL.
Testing
Run the test commands documented in the Testing section and confirm they pass.
Deployment
Follow the documented deployment steps for this project's target platform.
Interview Explanation
Use the Interview section to explain the architecture, technology choices and trade-offs.
Build Process
Phases guide the build in 9 checkpoints. Complete each and validate before moving on.
Interview Prep
30-second pitch
I built Kubernetes Production Application Platform — run a production-grade application platform on kubernetes. It uses Kubernetes, kubectl, Helm and solves production kubernetes demands security and reliability, not just working manifests.
2-minute walkthrough
Architect a production Kubernetes platform covering cluster architecture, workloads, networking, autoscaling and security hardening. The core requirements were Cluster setup, Secure workloads, Network policies. I structured the work around Design production clusters, Harden workloads, Scale properly and validated the result with the documented tests.
Architecture
The architecture is described by the interactive diagram in the Architecture section, which maps the request and deployment flows.
Why these technologies
I chose Kubernetes, kubectl, Helm, Security because they are the pragmatic, well-supported tools best suited to building a kubernetes of this kind.
Why this architecture
The structure exists to keep concerns separated, make each piece testable, and scale the project cleanly as requirements grow.
At scale
At scale I would introduce caching, move to a service boundary structure, add proper observability, and enforce stricter contracts between components.
What can fail
The data source becomes unavailable, A dependency introduces a breaking change, Performance degrades under load, Configuration drift between environments
Monitoring
Monitoring is covered in the Observability section, focusing on distributed metrics, logs, traces and SLOs.
Security
Security was handled by validating input, protecting secrets, and following the practices listed in the Security section.
Deployment strategy
Deployment follows the steps in the Deployment section for the target platform, with a health check to confirm success.
What I'd do differently
With more time I would add deeper test coverage, stronger observability, and automated deployment.
Practice Q&A
Why did you build Kubernetes Production Application Platform?
To demonstrate Design production clusters and Harden workloads on a real, portfolio-worthy project.
What was the hardest part?
Coordinating the pieces so each stays correct as the project grows, and validating end to end.
How do you handle failure and scale?
By designing explicit failure handling and scale considerations into the architecture.
Certification Alignment
CKA / CKAD style skills
Mirrors the skills examined in CKA/CKAD.
Extensions
- Add deeper test coverage
- Add observability and alerting
- Harden security
- Automate deployment