Interview Practice
Take-home & Review
Build a small feature with tests and a README, then defend it in review.
What interviewers evaluate
- Working code with tests
- A README with assumptions
- Defended trade-offs
- A credible next-steps list
What you will be asked
Extend an exercise into a small feature with tests and a README.
In the room
A time-capped offline build with a fixed scope, followed by a review of the code, the tests, and your trade-offs.
Timebox
2-4 hours plus a 45-minute review
Mock interview
A timed answer to a random question from this level, then the reference answer and your score.
How to practice
- Start with the linked take-home brief: build it in your own editor under its time cap, with tests and a README. The brief below is an alternative for a second attempt.
- Cap your time and write down what you skipped.
- With a peer: they review your work as if it were a real pull request and leave three comments.
What a strong answer shows
- The feature works and the scope is respected
- Tests cover the new behavior and at least one failure path
- The README lists assumptions, limits, and next steps
- You can defend one trade-off made under the time cap
Questions for this level
Each question opens on its Practice tab, and Previous and Next follow this list.
Tool Calling & Agents
4 h
Extend the validated ticket adapter with a paginated search_tickets tool behind a tool registry under a 3-hour cap, hand in tests and a README, then review a sample submission as the interviewer would.
Take-home brief
Extend the output validator into a small feature: a repair step for invalid output with a retry limit and a request deadline. Include tests and a README.
A strong answer covers
- A clear contract for the repair step and when it stops
- Tests for success, a repaired reply, a reply that stays invalid, and the retry limit
- A README with how to run it, the assumptions, and next steps
- No repair that invents a value the source does not support
Follow-up questions
An interviewer may ask these next.
- How would this feature fail in production?
- What would you add with another day?
- How did you decide what to leave out?
Scoring rubric
Interview ready at 8 of 10 with no 0.
| Dimension | 0 | 1 | 2 |
|---|---|---|---|
| Problem framing | Jumps to a solution or solves the wrong problem | Restates the problem but misses key constraints or success criteria | Clarifies goals, constraints, and success criteria before solving |
| Correctness | Key claims or code are wrong | Mostly right with gaps or unhandled cases | Correct and precise, including edge cases |
| Evidence or testing | No way to verify the answer | Generic testing ideas | Concrete fixtures, metrics, or traces that would confirm or refute the approach |
| Trade-offs | One option, no alternatives | Names alternatives superficially | Compares options against the stated constraints and says what would change the decision |
| Communication | Disorganized or unclear | Understandable but meandering | Structured and concise; states assumptions; checks in with the interviewer |