kilo-cv/docs/plans/2026-02-23-ci-parallelization-design.md

CI Parallelization Design

Overview

Parallelize GitHub Actions workflows to reduce total CI time by running independent tasks concurrently and sharing build artifacts between jobs.

Scope

• ci.yml
• release.yml
• staging.yml
• nightly.yml

Approach

Use artifact sharing to avoid redundant builds. Frontend build artifacts are uploaded once and downloaded by dependent jobs.

Design

ci.yml

1. Remove lighthouse dependency - currently waits for frontend unnecessarily
2. Upload frontend artifact - frontend job uploads dist/
3. Download artifact in test jobs - integration, e2e, regression download instead of rebuilding
4. Split quality job into 3 parallel jobs:
   • coverage - runs tests with coverage, uploads to Codecov
   • bundle-size - checks bundle size limits
   • security - runs npm audit

Job graph:

commitlint ──────┐
frontend ────────┼──► integration
backend ─────────┤
                 ├──► e2e
                 ├──► regression
                 │
lighthouse ──────┘ (parallel, no deps)

coverage ──────── (parallel)
bundle-size ───── (parallel)
security ──────── (parallel)

release.yml

Split monolithic job into parallel jobs:

1. lint - runs npm run lint
2. frontend-test - runs npm run test:run
3. backend-test - runs backend npm test
4. build - waits for lint + tests, uploads dist artifact
5. release - semantic-release (waits for build)
6. docker - unchanged, waits for release

Job graph:

lint ──────────┐
frontend-test ─┼──► build ──► release ──► docker
backend-test ──┘

staging.yml

Split into 2 jobs:

1. test - lint + frontend tests + backend tests in parallel steps
2. deploy - waits for test, builds and pushes docker

Job graph:

test ──► deploy

nightly.yml

Split into 2 jobs:

1. build - builds frontend, uploads artifact
2. docker - waits for build, pushes docker image

Job graph:

build ──► docker

Implementation Notes

• Use actions/upload-artifact@v4 and actions/download-artifact@v4
• Artifact retention: 1 day (sufficient for workflow duration)
• No changes to actual test/build logic, only workflow structure

Implementation Complete

• Task 1: ci.yml lighthouse parallelization and artifact sharing
• Task 2: ci.yml quality job split into parallel jobs
• Task 3: release.yml parallel lint, frontend-test, backend-test, build, release
• Task 4: staging.yml split into test and deploy jobs
• Task 5: nightly.yml split into build and docker jobs