About DevOtts/parallel-lifecycle
Git worktrees isolate your files. They do nothing about everything else. The moment you run two coding sessions at once, both want port 3000, both hit the same local database, and both reach for the same browser. They overwrite each other's dev servers, corrupt each other's test data, and serialize on a single Chrome. Most "fixes" auto-increment the port ("3000 busy, use 3001") — which quietly points your test harness at the wrong URL, so it tests nothing and passes anyway.