Practice mode · free · unlimited · not certifiable
CI Pipelines
Unscored tasks with hints and instant feedback. Practice results never become credentials.
Short lesson
Git recovery toolkit · 10 min
git stash for quick context switches, git reflog to find lost commits, git bisect run to find the first bad commit, git worktree add for parallel work.
L3Why does CI fail?spot
The build log says “npm ERR! engine Unsupported: requires node >=20” and tests never ran. Click the pipeline lines that cause the failures.
Sign up to practiseL5Knowledge checkmcq
Image builds take 9 minutes because dependencies reinstall every time. What fixes it?
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