Microfrontends Deployment Checklist

Version: 1.1.0 | Updated: 2026-07-16

Purpose

Gate promotion and rollback of a Microfrontends domain slice, shell contract, route, federated remote, shared package, or independent frontend release.

Why

A syntactically valid Microfrontends artifact can still fail because of eager shared-module consumption or share-scope initialization, unsatisfied singleton/range or duplicate framework runtime, remote entry unavailable, stale, or blocked by CSP/CORS, shell/slice route collision, cross-slice event/state contract drift. Promotion therefore requires target-state and rollback evidence.

How

Run against the exact target and immutable candidate. Preserve outputs from run each slice's immutable install, type-check, test, and production build independently; emit and inspect webpack stats (webpack --profile --json > stats.json) when Module Federation is used; request remote entry and chunks with curl -I <immutable-asset-url> to verify cache, CORS, CSP, and content type; execute shell contract tests against the current and next remote manifests; measure duplicate dependencies and route Web Vitals in the assembled production build. Stop promotion on any failed item.

Version-aware caution

Capture shell, bundler/module-federation plugin, framework, router, browser targets, and deployed remote manifests. Share-scope and runtime-loading semantics depend on exact host/remote bundler versions and cannot be inferred from source alone.

Tradeoffs

Promotion waits for "host and remote compatibility matrix passes for current and candidate versions" and "remote entry/chunks are immutable, integrity-aware where supported, and have correct cache/CORS/CSP headers". Those Microfrontends target checks slow release but directly bound eager shared-module consumption or share-scope initialization and make this rollback executable: Update the runtime manifest or feature flag to the prior immutable remote asset set; keep the shell contract backward compatible until all cached tabs and remote versions age out.

Anti-patterns

• Splitting page widgets among teams creates chatty runtime coupling without independent domain ownership or deployability.
• Do not remove a native warning, validator, policy, or safety limit merely to make generated output pass.
• Do not claim a successful result without preserving the command, target, artifact/revision, and observed output.

Enterprise considerations

Microfrontend governance owns shell contracts, route allocation, shared-dependency policy, CSP origins, accessibility baseline, telemetry schema, and decommission windows.

Official sources

• Module Federation
• HTML custom elements
• Micro Frontends architecture

Checklist

• host and remote compatibility matrix passes for current and candidate versions.
• remote entry/chunks are immutable, integrity-aware where supported, and have correct cache/CORS/CSP headers.
• route, authentication, navigation, analytics, and accessibility contract tests pass assembled.
• failure injection proves an unavailable remote renders a bounded fallback.
• RUM identifies shell, remote, and shared-dependency versions.
• canary watches remote-load errors, duplicate runtime, route errors, Web Vitals, and business conversion.
• manifest/feature flag can remove the slice without redeploying unaffected domains.
• rollback selects the previous remote manifest while retaining shell contract compatibility.
• Update the runtime manifest or feature flag to the prior immutable remote asset set; keep the shell contract backward compatible until all cached tabs and remote versions age out.
• Evidence identifies version, target, artifact/revision, command or manual method, UTC time, and result.

Changelog

• 1.1.0 (2026-07-16): Replaced generic gates with native Microfrontends evidence and failure controls.
• 1.0.0 (2026-07-16): Added initial checklist.