Practical AWS Guide: Building a Task Management SaaS in Production with Terraform
As of this writing (July 2026), the Terraform code in this series has been run through terraform fmt and terraform validate using Terraform v1.13.5 and the AWS provider v6.53.0. What validate guarantees only goes as far as syntax and consistency with the provider schema — it does not guarantee the result of actually applying the changes to AWS. Steps that involve an apply are written based on the official AWS and HashiCorp documentation, and each chapter cites its sources. AWS specification values (limits, defaults) also reflect information current as of this writing.
This series is a guide that takes you from introduction to practice, using the production environment of the fictional task management SaaS "Tasuku" as its subject and building up the design and Terraform implementation of seven major AWS services chapter by chapter. The seven services covered are VPC, Route 53, S3, ALB, ECS, RDS, and IAM. ECR, ACM, CloudWatch Logs, and Secrets Manager, which are indispensable to the architecture, are also covered within the chapters that use them.
The order of the chapters isn't for the convenience of the explanation — it follows the dependency order in which the infrastructure is actually built. Chapter 2 starts from the minimal Terraform configuration, and as the chapters progress, resources are added to the same codebase. By Chapter 10 the application is published, Chapter 11 covers environment separation, and Chapter 12 brings operations to a close.
Intended audience
- Those with experience developing web applications but no experience designing an AWS production environment from scratch
- Those who have used AWS through the console but want to learn how to manage it as code with Terraform
- Those who have read individual articles about ECS or RDS but want to follow the connections between services (networking, permissions, name resolution) end to end
This series does not cover the steps for creating an AWS account itself. It does not assume prior knowledge of the IAM permission model or VPC networking concepts — each chapter explains the concepts from the ground up at the start.
Final architecture
By the end, you'll have the following architecture. A user's request is resolved by Route 53, has its HTTPS terminated at the ALB, and reaches ECS (Fargate) in a private subnet. Data is stored in RDS (PostgreSQL) and S3.
Series structure
| Chapter | Theme | Overview |
|---|---|---|
| 01. Overview | Requirements and blueprint | Requirements definition for Tasuku, role division across the seven services, and how to think about build order |
| 02. Terraform Basics | The starting point for IaC | Minimal HCL syntax, the concept of state, and creating a budget alert with your first apply |
| 03. IAM | The permission model | Reading and writing policy JSON, roles and trust policies, and a practical approach to Terraform execution permissions |
| 04. VPC | Networking | CIDR design, 2 AZs with a 3-tier subnet layout, and cost trade-offs for the NAT Gateway |
| 05. S3 | Object storage | Bucket design principles, best practices for managing tfstate, and the attachments bucket |
| 06. ALB | The entry point | Layer 7 load balancer concepts, access logs, and publishing over HTTP first |
| 07. Route 53 and ACM | Names and certificates | DNS delegation, DNS validation for certificates, and publishing a custom domain over HTTPS |
| 08. ECS Part 1 | The container foundation | ECR, the cluster, task definitions, two kinds of IAM roles, and log design |
| 09. RDS | The database | Subnet groups, Secrets Manager integration, Multi-AZ, and completing the security group chain |
| 10. ECS Part 2 | Publishing the services | The two services, web and api, injecting secrets, and Auto Scaling |
| 11. Standardizing Deployment and Separating Environments | Connectivity checks and environment separation | An end-to-end connectivity checklist, a standard procedure for ECS deployment, and refactoring into modules with an envs/dev,prod structure |
| 12. Wrap-up | Billing structure and how it all ends | A map of the billing structure, cost-reduction patterns, a safe teardown procedure, and the next steps |
How to read this series
- If you're reading straight through: The chapter order is the build order as-is. From Chapter 2 onward, each chapter builds on the code from the previous chapters, so we expect you to read them in order.
- If you just want the concepts: You can skim just the first half of each chapter (roles, concepts, and design decisions). The Terraform implementation sections stand on their own.
- If you only want a specific service: You can check where that service sits in the overall picture using the build-order diagram at the start of each chapter (which highlights the current chapter in orange), then start reading from there.
The architecture in this series includes resources that start incurring hourly charges from the moment they are created (NAT Gateway, ALB, RDS, and others). Some chapters explicitly note when billing begins, and Chapter 2 creates a budget alert as the first resource. Chapter 12 reviews the billing dimensions for the whole series in one place. We don't state specific prices in the text, since they're subject to revision. If you try this yourself, be sure to check current pricing on the AWS pricing page and delete any resources once you're done with them.
Now, let's start with Chapter 1: Overview.