awsclouddevopsplatform-engineeringterraformarchitecturesecuritycompliance

Why You Shouldn't Reinvent Your AWS Architecture

Erik Osterman
byErik OstermanCEO & Founder of Cloud Posse
May 15 2025

"We thought we were building something custom. Turns out we were just rebuilding what already existed — badly."

If you've been in engineering long enough, you've seen this movie before.

A new platform initiative kicks off. Leadership says, "Let's design our AWS architecture from scratch — tailored to our needs!" The team dives in. Weeks become months. Edge cases pile up. The architecture gets more "unique" — and more brittle. Meanwhile, the business is still waiting for features to ship.

Here's the truth most teams figure out too late:

A battle-tested, opinionated reference architecture is a better starting point than building a custom AWS architecture from zero.

This post will show you why — and give you permission to choose the simple, proven path.

Why "Opinionated" Is a Feature, Not a Bug

Engineers sometimes bristle at the word "opinionated."

We want flexibility.

We don't want to be locked in.

Our use case is special.

But let's be blunt: every architecture is opinionated. The only question is whether those opinions are:

  • Proven through battle-tested use across many teams
  • Aligned with AWS best practices and ecosystem trends
  • Designed to help you move faster

Or...

  • Invented on the fly
  • Based on partial information
  • A series of accidental choices made under deadline pressure

An opinionated reference architecture encodes hard-won experience so your team doesn't have to learn everything the hard way.

That's not a constraint — it's leverage.

How Starting From Proven Patterns Beats Starting From a Blank Slate

Starting from a blank slate feels empowering — until it's not.

Here's what typically happens when teams go "blank slate":

  1. The first version is too simple.
  2. Early decisions get baked in before anyone sees the downstream effects.
  3. New requirements expose gaps.
  4. Workarounds pile up.
  5. The architecture becomes fragile, inconsistent, hard to evolve.

Meanwhile, starting from a proven, opinionated reference architecture gives you:

  • A solid multi-account foundation
  • Known-good patterns for IAM, networking, logging, observability
  • Compliance-aligned defaults
  • Consistent CI/CD and GitOps workflows
  • The confidence that it scales — because others have already scaled it

Put bluntly: you don't earn a competitive edge by reinventing account factory patterns or IAM role hierarchies.


Why Copying From the Internet Doesn't Work

Here's another common trap:

We'll just copy some Terraform modules from GitHub.

Good luck with that.

The internet is full of fragmented, one-off examples:

  • Modules that don't compose well together
  • Outdated patterns that no longer align with AWS best practices
  • Code that works in one narrow context, but breaks in yours
  • Lack of end-to-end integration and testing
  • No guidance on how to evolve or operate the architecture over time

It's like trying to build a car by stitching together random parts from different manufacturers.

What "Battle-Tested" Really Means in the Context of Terraform Modules and AWS

Battle-tested Terraform modules and architecture patterns are:

  • Used across dozens of real production environments
  • Validated in multiple industries — including regulated ones
  • Designed to handle common compliance requirements
  • Regularly updated to align with evolving AWS services
  • Composable and consistent across the stack

By contrast, most DIY efforts are:

  • Unproven beyond the team that built them
  • Inconsistent in conventions and composition
  • Missing critical "table stakes" features
  • Dependent on one engineer's tribal knowledge
  • Quickly out of date as AWS evolves

Why Cloud Posse's Architecture Gives You an "Unfair Head Start"

At Cloud Posse, we've spent years refining an opinionated, battle-tested reference architecture for AWS — built on open-source Terraform modules and proven platform engineering practices.

We've seen the traps teams fall into when they try to reinvent this from scratch. That's why we designed our architecture to give customers an unfair head start:

  • Production-grade AWS foundation in weeks, not months
  • Skip years of trial-and-error learning
  • Proven patterns that scale across accounts and teams
  • Compliance readiness from day one
  • Freedom for engineers to focus on delivering value

Permission to Choose the Simple, Proven Path

If you're an Engineering Manager weighing your options, here's your permission slip:

You do not need to reinvent your AWS architecture.

Doing so is:

  • A slow path to risk and technical debt
  • A distraction from building what differentiates your business
  • A drain on your best engineers' time

Cloud Posse: What We Do

We've helped dozens of companies avoid the reinvention trap:

  • Startups building greenfield platforms
  • Enterprises modernizing legacy AWS environments
  • Regulated businesses where compliance isn't optional

Our open-source reference architecture and frameworks give teams a head start — so they can ship faster, with less risk, and more confidence.

Final Thought

Every month you spend designing your snowflake AWS architecture — or debating what you should build — is a month your product isn't shipping, your team isn't moving, and your leadership is asking why.

If you'd rather skip the wasted cycles and start from what works, we can help. You'll have it built and running before most teams finish arguing on the best way to do things.

Talk to an engineer and see if it's a fit.

Erik Osterman
Erik Osterman
CEO & Founder of Cloud Posse
Founder & CEO of Cloud Posse. DevOps thought leader.

Share This Post