PROVE HOW YOU WORK WITH AI
Everyone has an agent. Show you can drive one.
You solve scenarios with your agent — every prompt captured automatically — then defend your decisions under time pressure. The trace is the test.
Timed runs
Prompt budgets and clocks beat copy-paste.
Trace defense
Justify your own decisions, not a borrowed answer.
Credibility passport
Defense traces, not green ticks.
HOW IT WORKS
- 01
Practice with your agent
Requirements arrive in stages. Prompts are captured for you.
- 02
Unlock Ranked
Pass 5 practice scenarios to enter counted runs.
- 03
Defend the trace
Timed questions on your code, choices, and prompts.
- 04
Bank your passport
Defended scores land on your passport as proof.
Practice
Learn the system. Repeatable, unscored, no defense.
Ranked
Counted runs. Finish, defend under time, score your passport.
Agent scenarios
All scenarios →Pair Sum
Easy · Hash Map · Arrays · 20m
Find two numbers that add to a target and return their positions. Walk the list once, remembering each number seen: for two_sum([2, 7, 11, 15], 9), 9 - 2 = 7 is already seen, so the answer is [0, 1].
Merge Sweep
Medium · Sorting · Intervals · 25m
Fold overlapping time ranges into one clean cover. Sort by start, then sweep: [1, 3] and [2, 6] overlap into [1, 6], while [8, 10] and [15, 18] stand alone.
Rate Limit
Medium · Sliding Window · Arrays · 25m
Guard an API: each request is allowed only while fewer than capacity already-allowed requests sit inside the window. With capacity 2 and window 5, requests at [0, 1, 2, 3] give [1, 1, 0, 0] — denied requests never consume quota.
Retry Backoff
Medium · Math · Simulation · 25m
Schedule waits between retries that grow exponentially but never pass a cap. With base 1, factor 2, cap 5 over 4 failures: waits are 1, 2, 4, then 8 capped to 5 — [1, 2, 4, 5].
Meeting Rooms
Medium · Sorting · Intervals · 25m
Book the fewest rooms that fit every meeting. Sort starts and ends, then sweep: meetings [9, 10] and [10, 11] touch but never overlap, so 1 room is enough — an ending meeting frees its room first.
Top Error
Medium · Hash Map · Strings · 25m
Read a failing service log and name the most frequent error code. For [500, 404, 500] the answer is 500 (seen twice); ties break to the smallest code string, so [404, 500] returns 404.
Allocate Stock
Medium · Greedy · Arrays · 25m
Play warehouse keeper: walk each order in turn, fulfill it if stock remains, and never let a skipped order block a later one. With stock 6 and orders [4, 2, 5]: 4 fits (2 left), 2 fits (0 left), 5 does not — [1, 1, 0].
Valid Rows
Medium · Filtering · Arrays · 25m
Scrub a signup sheet, keeping rows with age 18-99 and ZIP 10000-99999, bounds inclusive. For ages [25, 17, 30] and ZIPs [12345, 90210, 999]: row 0 is valid, row 1's age fails, row 2's ZIP fails — [0].
Overbooked Slots
Hard · Sweep Line · Intervals · 30m
Audit a room calendar with a capacity limit and flag every meeting past capacity, in sweep order. With capacity 1 and meetings [9, 11], [10, 12]: the second starts while the first still runs, so index 1 is flagged.
Agent duels
you + your agent vs a simulated house pace · first green winsWatch its progress live while you work. Beat it to earn credits toward harder difficulties.
Open duels →Bring your own agent
Pair your own coding agent and solve scenarios with it — chat, edits, and approvals stay in Codelit.