Why Most "Composable" Architectures Still End Up Tightly Coupled
Composable architecture is often presented as the antidote to monolithic platforms. In theory, loosely coupled systems enable flexibility, resilience, and faster change. In practice, many composable architectures become just as brittle as the systems they replaced.
The reason is rarely the technology. It is the design.
The promise vs the reality
Composable platforms promise:
- •Independent evolution of systems
- •Clear separation of concerns
- •Reduced vendor lock-in
What often emerges instead:
- •Hidden dependencies
- •Shared business logic scattered across systems
- •Tight coupling disguised behind APIs
Where coupling creeps in
Business logic leakage
Logic that should live in one domain (pricing, eligibility, product rules) often ends up duplicated across:
- •CMS
- •Commerce
- •PIM
- •DAM
Once duplicated, systems cannot evolve independently.
Overloaded integrations
APIs become:
- •Chatty
- •Context-heavy
- •Fragile under change
Without clear contracts, integrations become implicit dependencies.
Ownership confusion
Composable architectures fail fastest when:
- •No one owns the end-to-end flow
- •Teams optimise locally, not systemically
- •Architectural decisions are deferred "until later"
What actually works
Successful composable architectures share common traits:
- •Clear domain boundaries: Each system owns a well-defined business capability
- •Explicit data ownership: Single source of truth for each data domain
- •Minimal, well-defined integration contracts: APIs that are stable and purpose-built
- •Strong architectural governance: Consistent patterns enforced across teams
Loose coupling is an outcome of discipline, not a default feature of composable tools.
The uncomfortable truth
Composable architecture increases the need for strong solution architecture — it does not reduce it. Without senior architectural oversight, composability simply redistributes complexity instead of reducing it.
Final thought
Composable platforms are powerful. But without clarity, they create the illusion of flexibility while locking organisations into fragile, hard-to-change systems.
The difference lies not in the tools chosen, but in the architectural decisions made early — and enforced consistently.
Key Principle: Composable architectures require more architectural discipline, not less. Success comes from clear boundaries, explicit ownership, and strong governance — not from the tools themselves.
