Case Study: A Full Technical Screen, Solved Step by Step
Work through a 90-minute technical screen covering three tasks: implementation, SQL queries, and API interaction. Inspect all tasks before coding, allocate time effectively, and maintain a decision log to track progress. Apply critical thinking to each task, anticipate common pitfalls, and verify outputs against hand-calculated predictions. Communicate assumptions clearly, handle errors systematically, and ensure accuracy throughout the assessment.
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A full screen combines an implementation task, a SQL query and an API task under one deadline. Below, each task is solved under a clock, with the checks that justify each move.
The screen below is a reconstruction built from public preparation reports, not a real Palantir assessment. Use it to rehearse the method, not to predict questions.
The screen
It is a 90-minute practice assessment with three tasks. Navigation is free, and you can run your own code. No scoring weights are shown.
Implementation: Roll up inventory changes per warehouse and SKU.
SQL: Count open support tickets and their total severity per region.
API: Total the cost of incidents from a paginated endpoint.
Minutes 0–5: Inspect, then budget
Read all three prompts before writing any code. For each one, note what the output row represents and which rule is most likely to be misunderstood.
Budget for this screen
0–5: inspect all tasks
5–30: Task 1
30–55: Task 2
55–80: Task 3
80–90: final verification of all three
Each task block ends with a runnable baseline and at least one check. If a block runs over, save what works, write a note, and move on.
Keep a decision log: At each checkpoint, write one line: the time, what is verified, and your next move. For example: 22:00 — Task 1: 4 checks pass. Switching to Task 2 early. It takes seconds, and it stops you from losing track of what is actually done. In a live screen, say the same line aloud.
While inspecting, the candidate notices that each task depends on one thing that must be preserved exactly:
Task 1: Every row contributes, then the totals are sorted.
Task 2: The governing event, meaning the latest one, decides each ticket’s status before anything is summed by region.
Task 3: Each immutable ID counts ...