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Bump the infrastructure jest job from --maxWorkers=2 to --maxWorkers=100%. On the 4-vCPU ubuntu-24.04 runner the old cap left half the cores idle (jest's own default there is 3 workers). With the backend suite now parallel (#1111), the infra job is the PR long pole at ~6m30s; ts-jest + CDK synth is CPU-bound so it parallelizes well. 16 GB RAM comfortably fits 4 workers.
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Closing: measured regression — infra jest went 392s (--maxWorkers=2) to 977s (--maxWorkers=100%), 2.5x slower. ts-jest re-runs type-checking per worker with no shared cache and CDK synth is memory-heavy, so extra workers thrash. Correct fix is a cheaper per-worker transform (transpile-only) plus a single shared tsc gate, not more workers. |
DerrickF
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Sep 15, 2026
Make ts-jest transpile-only (isolatedModules) so jest workers stop re-type-checking the whole project each — the dominant cost of the infra suite (the long pole once backend went parallel in #1111). Add a single 'tsc --noEmit' (npm run build) step to the infra CI job so type safety is preserved on PRs (previously only ts-jest enforced it; tsc ran only in teardown.yml). Workers stay at 2 (the --maxWorkers bump regressed 2.5x in #1112). No const enum in the tree, so isolatedModules is safe. Verified: tsc clean; 178 tests green transpile-only.
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What
Bumps the infrastructure jest job from
--maxWorkers=2to--maxWorkers=100%. With the backend suite parallelized in #1111, the infra job became the PR long pole (~6m30s). The old cap left half the runner's cores idle — jest's own default on a 4-vCPU box is 3 workers, so 2 was below default.Why it's safe
Measurement
Baseline infra job: ~6m32s (
--maxWorkers=2). Target: this PR's ownTest infrastructure (jest)run — comparing the two is the proof.Follows #1111 (backend pytest xdist: ~572s → 318s).