Test supported runtimes concurrently

Give each target framework its own job that installs only what it needs.

Prompt

Evaluate and apply this CI technique to my repository: Test supported runtimes concurrently.

Give each target framework its own job that installs only what it needs.

Read the technique and its source-backed company examples: https://starsling.dev/ci-playbooks/techniques/matrix-by-supported-runtime.md

Inspect this repository’s CI workflows, build and test commands, dependencies, and recent run timings. Identify where this technique applies and explain the expected benefit using this repository’s evidence.
Measure a baseline from recent comparable runs: elapsed time, queue time, runner minutes and failures where available. If data is unavailable, say what cannot be measured.
Compare relevant company approaches, checking prerequisites, platform differences and tradeoffs. Rank applicable options by evidence, fit and measurable opportunity; do not present company results as predictions for this repo.
Recommend the smallest safe change, show what checks and fallback paths remain, and ASK ME WHICH CHANGE TO APPROVE BEFORE EDITING ANY FILES.
Only after approval, work on a new feature branch, make one reversible change, and open a reviewable pull request. Never merge or push to a default or protected branch.
Keep required checks, test coverage, deployment and release behavior intact. Validate the change and compare equivalent runs where possible; report limitations and what should be monitored after merge.

View all playbooks

How Stripe used this technique

Read what Stripe changed and follow the original sources.

Test supported runtimes concurrently

Stripe .NET replaced one sequential build-and-test job with per-framework matrix jobs and a native Windows .NET Framework lane. Each lane installs the latest SDK plus only its target runtime, and example builds run in their own job.

Use it when: A multi-runtime suite runs sequentially or installs every toolchain in every lane.
Before applying it: Keep every supported runtime gated, let every diagnostic matrix leg run to completion, and update branch protection for the new job names.

How Stripe used this technique

Test supported runtimes concurrently

Related techniques

Balance test work across shards

Split independent work off the longest job

Split long test suites across runners

Company Playbooks

Related guides

Shard tests across parallel jobs

Cut repeated test setup

Diagnose slow tests in CI

Optimize Playwright tests

Make Vitest run mode explicit

Filter workflows by changed files