Build Modules That Scale: Best Practices for Layout and Design

Selected theme: Best Practices for Module Layout and Design. Explore pragmatic patterns, cautionary tales, and field-tested checklists for cohesive, testable modules that stay joyful to maintain. Subscribe and share your favorite module design wins.

Define Clear Boundaries and Cohesion

Single Responsibility at the Module Level

Treat each module as a unit with one reason to change. When we moved payment validation out of our checkout module, onboarding sped up, defects dropped, and code reviews became dramatically easier to reason about. What responsibility can you split today?

Stable Interfaces, Evolving Internals

Keep the public surface steady while letting the internals breathe. A thin facade plus adapters let us overhaul a pricing engine without breaking clients. Announce the contract, document expectations, and ask readers to challenge unclear behaviors.

Use Domain Language in Names

Name modules after the business concept, not the technology. “InventoryReservations” beats “data-utils.” A shared vocabulary avoids guesswork, accelerates reviews, and protects intent during refactors. Tell us which names in your codebase carry surprising clarity.

Layout Patterns That Age Well

Grouping by feature keeps context local: UI, domain, and storage live together behind a module boundary. We trimmed navigation time and reduced accidental coupling. If a concern becomes truly shared, extract it deliberately, never by default.

Draw a bright line between what’s exported and what stays private. Use /public or an index file for the API, /internal for helpers, and lint rules to enforce access. Future you will say a grateful thank you.

Prefer a single entry file that reveals intent: exports, types, and usage snippets. Avoid leaky barrel files that re-export everything. We cut churn when newcomers saw only the supported surface, not the backstage wiring.

Keep Dependencies Acyclic

Adopt import conventions like feature → shared, never sideways. Enforce with tools such as ArchUnit, ESLint import rules, or Deptrac. Once we added automated checks, a nasty midnight cycle vanished before it reached production.

Keep Dependencies Acyclic

When two modules need each other, invert toward an interface in a stable home. Plugins depend on contracts, not concrete implementations. That move let us swap a search provider without touching five downstream features.

Keep Dependencies Acyclic

Make architecture rules non-optional. A pre-commit hook catches quick mistakes; CI blocks merges that violate boundaries. The first week hurts, the second week teaches, and the third week feels wonderfully quiet.

Keep Dependencies Acyclic

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.

Design a Minimal, Friendly Public API

If it isn’t documented, don’t export it. We deleted a catch-all utils export and instantly reduced misuse. Curate a short list of verbs, types, and events that communicate exactly how to use the module.

Design a Minimal, Friendly Public API

Use semantic versioning within your workspace or tags in a monorepo. Mark deprecations, add adapters, and publish upgrade notes. A gentle path buys trust, and trust buys time for meaningful improvements.

Performance, Build, and Delivery Considerations

Isolate Builds and Cache Aggressively

Small, independent modules unlock incremental builds and remote caches. With Bazel and task graph execution, we shrank CI time by 40%. Your developers will notice—and thank you—after the first faster feedback loop.

Tree-Shaking and Dead Code Discipline

Prefer pure, side-effect-free files and named exports. Avoid deep, implicit imports that confuse bundlers. After pruning re-exports, our bundle dropped megabytes without a single feature loss. What dead weight could you trim today?

Runtime Composition and Lazy Loading

Compose features via registries and dynamic imports so heavy modules load only when needed. This pattern kept our mobile memory footprint low and responsiveness high. Share where you’ve applied lazy boundaries successfully.

Join our mailing list

Build Modules That Scale: Best Practices for Layout and Design

Define Clear Boundaries and Cohesion

Single Responsibility at the Module Level

Stable Interfaces, Evolving Internals

Use Domain Language in Names

Layout Patterns That Age Well

Keep Dependencies Acyclic

Keep Dependencies Acyclic

Keep Dependencies Acyclic

Keep Dependencies Acyclic

Design a Minimal, Friendly Public API

Design a Minimal, Friendly Public API

This is the heading

This is the heading

Performance, Build, and Delivery Considerations

Isolate Builds and Cache Aggressively

Tree-Shaking and Dead Code Discipline

Runtime Composition and Lazy Loading