xAI interview questions for engineers

Topic tags
Python
Concurrency

Reported interview periodNov 2025–Apr 2026

Make a Bank Account Thread-Safe

You are given a BankAccount whose deposit method performs a read-modify-write operation and may pause between reading and writing. You cannot modify that class. Implement a subclass that makes deposits safe whe…

Practice focusCall the inherited implementation rather than copying it. Two deposits of 500 and 700 into an account starting at 0 must finish with 1200 . Ensure the lock is released if the inherited method raises. The supplied constructor creates the account and its lock. Complete deposit only. The provided run case adapter owns the concurrent fixture execution; it is not candidate work. Opening balances and deposit amounts are integers, and deposit amounts are nonnegative. Empty deposit lists leave the opening balance unchanged. Each successful call returns None .…

Public brief

Topic tags
Python
Concurrency

xAICoding

Talk-through codingNo local grader

Reported interview periodDec 2025–Jan 2026

Sort Integers with Multiple Workers

Implement an ascending integer sort that divides sufficiently large inputs into chunks, sorts chunks concurrently, and merges the sorted runs.

Practice focusReturn a new list and do not mutate the input. For fewer than 1000 values or a single worker, a direct sort is acceptable. On the large-input path, actually partition the input and dispatch chunk sorts; do not sort the entire list in one call. Cap the worker count to useful work and merge all runs correctly, including duplicates and negative values. The worker count must be a positive integer (not a boolean); reject invalid counts with ValueError before dispatch. Use native worker execution for the concurrent path.…

Public brief

Topic tags
Data structures
Concurrency
Storage & state
Reliability
ML / AI

System designSystem designAI-generated

Written response75–100 min

Reported interview periodN/A

Build a reliable job runner

Review staged prompts that begin with a small in-memory worker, then introduce retries, duplication, cancellation, and process restarts.

Practice focusState modeling, Idempotency, Retry policy, Failure recovery, Operational reasoning through a written response exercise.

Public brief

Topic tags
Concurrency
Reliability
Security
Product design

xAISystem designAI-generated

Written response45–60 min

Reported interview periodN/A

Design durable scheduled publishing

A posting product lets an author write now and publish later. Design the path from submission to publication, then keep it correct when authors edit, cancel, and retry while delivery fans out to followers.

Practice focusDurable scheduling, Idempotency, Race conditions, Time zones, Operational telemetry through a written response exercise.

xAI interview questions for engineering roles

xAI interview questions for engineering roles

What candidates report about the interview

Make a Bank Account Thread-Safe

Sort Integers with Multiple Workers

Build a reliable job runner

Design durable scheduled publishing

What candidates report about the interview

Make a Bank Account Thread-Safe

Sort Integers with Multiple Workers

Build a reliable job runner

Design durable scheduled publishing