Challenges

The catalogue you train on: real bugs, features and diffs, each credited to the open-source project and the commit that fixed it.

4
Debug
graded on root cause, scope of the fix, regression test
3
Build
graded on behaviour, blast radius, tests written
3
Review
graded on what was caught, what was missed
0 of 10
Published
credited to a project, an issue and a fixing commit
#ChallengeModeSkillAttemptsSource
47 The silent failure
POST /checkout returns 200. Orders are not in the database. No errors in the logs. Customers are complaining.
 Debug Observability 2 Draft — no fix attached
48 Orders return 200 and never reach the database Debug Debugging 1 Draft — no fix attached
49 Memory climbs for six hours, then the pod restarts Debug Performance 1 Draft — no fix attached
50 The migration locks the table it was meant to widen Debug Databases 4 Draft — no fix attached
51 Paginate an endpoint that returns the whole catalogue Build APIs 1 Draft — no fix attached
52 Make the retry idempotent without changing the public API Build APIs 1 Draft — no fix attached
53 Backfill a column on a live table with no write lock Build Databases 2 Draft — no fix attached
54 A pull request that passes every test and drops a tenant filter Review Security 1 Draft — no fix attached
55 The diff behind last Friday's incident, before it shipped Review Code review 2 Draft — no fix attached
56 A cache put in front of a read that goes stale Review Code review 2 Draft — no fix attached

Your skills

Eight skills, one rank each. A rank moves only when a challenge in the skill is solved with every test green and no hint: everybody starts at I entering, II working at 3, III fluent at 8, IV trusted at 15 distinct challenges. Solving one twice counts once, and a rank never goes down.

SkillRankChallenges in the catalogue
Debugging I entering 1
Observability I entering 1
Databases I entering 2
APIs I entering 2
CI/CD I entering 0
Security I entering 1
Performance I entering 1
Code review I entering 2