Engineering

Composable vs Configurable Architecture

When to compose building blocks and when to expose configuration knobs — algebraic foundations, convention trade-offs, cognitive load, feature flags, drift, platform engineering, and monolith-to-microservices topology decisions.

9 modules

The Core Tradeoff

Composability, configurability, and modularity are three distinct properties — and conflating them is where most architectural decisions go wrong.

The Algebraic Foundations of Composition

Why functor, monad, and monoid laws give you something configuration switches never can: guarantees

Convention Over Configuration

How frameworks encode architectural decisions as defaults — and what happens when those defaults stop fitting

Cognitive Load and Decision Fatigue

Architectural choices have a measurable human cost — and it must be designed for

Composition Failure Modes

When the pieces fit but the system breaks

Runtime Optionality and Feature Flags

Deferring configuration decisions to production — and paying the price if you don't manage them

Infrastructure Configuration Drift

The long-run cost of configurability without discipline

Platform Engineering and Developer Experience

How internal developer platforms resolve composable-vs-configurable tensions at the organizational level

Architectural Topology: The Capstone Decision

Choosing between monoliths, modular monoliths, and microservices through the lens of team size, deployment discipline, and operational cost

How this plan was made

Each plan on learnings is built by a hand-crafted agentic pipeline: research agents gather primary sources, a claim reviewer verifies facts against them, and a sequencer orders modules for how people actually learn. The curation — topic selection, framing, editorial standards — is Nicolas's. The research and writing is AI-assembled.