Field notes / Sharding Playwright without chaos

Sharding Playwright without chaos

2026-01-18 · Hai Phong

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We start from a single repository that already runs Playwright locally. The goal is not maximum parallelism on day one, but predictable wall-clock time with a cost ceiling.

The post walks through naming folders by bounded context, then mapping those folders to shards with a simple JSON manifest checked into git. Reviewers can see which shard owns which feature area.

We end with a short checklist for artifact uploads so failures remain legible when runners are ephemeral. No vendor lock-in: the same manifest works on self-hosted Linux runners.