Projects
ProjectsCloud & InfrastructureadvancedInfrastructure

Terraform Modular AWS Platform

Reusable VPC, compute, database and security modules.

~24 hours 9 phases Capstone
TerraformAWSHCL

Overview

Create a modular Terraform platform with reusable VPC, compute, database and security modules, using remote state and locking.

The problem

Provision a full AWS platform from reusable Terraform modules.

Why it matters

This is a real, in-demand scenario: Provision a full AWS platform from reusable Terraform modules.. Teams that can ship and run a infrastructure like this solve an actual business need and are hired for that ability.

What you'll build

  • A module library
  • Complete AWS platform
  • Remote state

What you'll learn

  • Module design
  • AWS provisioning
  • State management

Business problem

Teams rebuild infrastructure instead of reusing proven components.

Technical problem

Build a module library that provisions a complete, secure AWS platform.

When you're done: A working infrastructure project — code committed, tests passing, and documented in your portfolio.

Requirements

User requirements

  • Reuse modules
  • Provision platform
  • Manage state

System requirements

  • Terraform
  • AWS
  • State

Functional requirements

  • Module VPC
  • Module compute
  • Module DB
  • Module security
  • Remote state

Non-functional requirements

  • Reusable
  • Secure

Technical requirements

  • module boundaries
  • terraform_remote_state
  • s3/dynamodb

Security requirements

  • No secrets
  • Least privilege
  • Encrypted

Operational requirements

  • Documented module usage

Constraints

  • Terraform

Success criteria

  • Modules reusable across envs
  • Remote state locked
  • Resources secured

Flows

Request Flow

  1. 1

    Browser

    User requests the application over HTTPS.

  2. 2

    CDN / DNS

    Edge routes the request to the origin.

  3. 3

    Load Balancer

    Distributes traffic across healthy app instances.

  4. 4

    Application

    Handles the request, applies business logic.

  5. 5

    Cache

    Serves fast reads for hot data.

  6. 6

    Database

    Persists data and returns results.

Project Structure

Root of the client application source.

Setup

  1. 1

    Prerequisites

    You need the tools required by Terraform, AWS, HCL installed and available on your PATH.

  2. 2

    Clone project

    Clone the repository locally.

    1. Clone the repository
    git clone <your-repo-url> <project-folder>
  3. 3

    Install dependencies

    Install the project dependencies.

    1. Initialize a Node.js project
    npm init -y

    Expected

    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. 4

    Configure environment

    Set the environment variables documented for this project. Never commit secrets.

    1. Create the environment file
    cp .env.example .env   # then edit values
  5. 5

    Start project

    Run the development command and confirm it starts.

    1. Start the development server
    npm run dev

    Expected

    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. 6

    Verify

    Open the printed local URL and confirm the primary flow works.

Build Phases

0 of 9 phases complete

  1. Objective: Establish the next milestone of the cloud infrastructure.

    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 project
    npm init -y

    Expected

    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.

  2. Objective: Establish the next milestone of the cloud infrastructure.

    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 terraform package
    npm install terraform

    Expected

    Adds terraform 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.

  3. Objective: Establish the next milestone of the cloud infrastructure.

    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 server
    npm run dev

    Expected

    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.

  4. Objective: Establish the next milestone of the cloud infrastructure.

    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 production
    npm run build

    Expected

    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.

  5. Objective: Establish the next milestone of the cloud infrastructure.

    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.

  6. Objective: Establish the next milestone of the cloud infrastructure.

    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.

  7. Objective: Establish the next milestone of the cloud infrastructure.

    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.

  8. Objective: Establish the next milestone of the cloud infrastructure.

    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.

  9. Objective: Establish the next milestone of the cloud infrastructure.

    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

1. Initialize a Node.js project
npm init -y

Expected

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.

2. Install the terraform package
npm install terraform

Expected

Adds terraform 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.

3. Start the development server
npm run dev

Expected

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.

4. Build the application for production
npm run build

Expected

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 -y

    Success: All unit tests pass without errors.

Integration tests

  • Components integrate correctly with data sources and services.

    npm test

    Success: Integration tests pass for the primary flows.

API tests

  • Endpoints respond to valid and invalid input correctly.

    npm test

    Success: API tests cover happy and failure paths.

End-to-end tests

  • A user can complete the primary journey end to end.

    npm run test:e2e

    Success: The main user journey completes successfully.

Security tests

  • No obvious security regressions are introduced.

    npm audit

    Success: No high or critical vulnerabilities.

Debugging & Troubleshooting

Provider initialization fails

Why: The provider cannot be downloaded or is version-conflicted.

Check: Re-run init verbosely.

terraform init

Fix: Check network, registry access, and required_version constraints.

Prevent: Pin provider versions and document network requirements.

State lock conflict

Why: Another process holds the state lock.

Check: Identify the lock holder.

terraform apply   # wait for lock

Fix: Wait for it to release, or unlock if it is stale.

Prevent: Use locking backends (S3 + DynamoDB) and avoid concurrent applies.

Invalid variable or missing value

Why: A variable was referenced but not provided.

Check: Review variables.tf and the plan input.

terraform plan

Fix: Provide the value via tfvars, a variable block, or the CLI.

Prevent: Add validation blocks and sensible defaults.

Permission denied applying changes

Why: The credentials lack the required IAM permissions.

Check: Identify the failing resource and the error.

terraform apply

Fix: Grant the minimal permissions needed for the resource actions.

Prevent: Use least-privilege roles and test plans before applying.

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

  • Node and service logs shipped to a centralized sink
  • Infrastructure deployment logs

Metrics

  • CPU, memory, disk, network
  • Container metrics
  • Queue depth

Traces

  • Service-to-service traces

Health checks

  • Readiness and liveness probes
  • End-to-end health probe

Alerts

  • Resource exhaustion alerts
  • Unexpected downtime alert

Dashboards

  • Node, container and application dashboards

SLIs

  • Availability — Uptime of the service endpoints

SLOs

  • Availability — 99.9% over 30 days

Deployment

  1. 1

    Prepare for deployment

    Build the production artifact.

    1. Build for production
    npm run build
  2. 2

    Deploy

    Deploy to the project target platform following its documented steps.

    1. Deploy
    npm run deploy   # or the platform-specific command
  3. 3

    Verify

    Confirm the deployed application responds and its health check passes.

    1. Check health
    curl -I https://<your-deployed-url>

Documentation

Project Overview

Create a modular Terraform platform with reusable VPC, compute, database and security modules, using remote state and locking. This is a advanced infrastructure project in the cloud infrastructure space, built to demonstrate real engineering, not just copied code.

What You Will Build

- A module library - Complete AWS platform - Remote state

Problem Statement

Teams rebuild infrastructure instead of reusing proven components. Build a module library that provisions a complete, secure AWS platform.

Technology Stack

Terraform, AWS, HCL

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 Terraform Modular AWS Platform — provision a full aws platform from reusable terraform modules. It uses Terraform, AWS, HCL and solves teams rebuild infrastructure instead of reusing proven components.

2-minute walkthrough

Create a modular Terraform platform with reusable VPC, compute, database and security modules, using remote state and locking. The core requirements were Module VPC, Module compute, Module DB. I structured the work around Design module boundaries, Share modules, Manage remote state 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 Terraform, AWS, HCL because they are the pragmatic, well-supported tools best suited to building a infrastructure 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 Terraform Modular AWS Platform?

To demonstrate Design module boundaries and Share modules 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

HashiCorp Terraform Associate

Mirrors the Terraform Associate objectives.

ProvisioningVariablesStateModulesProviders

Extensions

  • Add deeper test coverage
  • Add observability and alerting
  • Harden security
  • Automate deployment

Completion Checklist

Prerequisite Projects