xAI interview questions for engineers

CANDIDATE-REPORTED · INDEPENDENT SYNTHESIS

What candidates report about the interview

3 reviewed signals

Use these reports to choose what to rehearse, not to predict a fixed loop. Formats vary by role, team, and date; confirm your current process with the recruiter. Frontier Rehearsal is independent and not company-endorsed.

Practice promptsOriginal exercises shaped by recurring preparation themes—not reported interview questions.1

Practice prompt (not a reported interview question): implement a small infrastructure-flavoured function with clear inputs and outputs, then compare your production-oriented solution with an algorithm-first alternative and justify which constraints matter most.
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Process signalsReported stages, formats, timing, and role-specific variations.2

According to candidate reports, xAI's 45-minute backend tech screen is a coding round that asks for something functional, such as an API endpoint or a data-processing function, with some architecture discussion but not a full system-design round.
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Candidate reports describe an xAI coding round delivered in Python and bash over about 45 minutes, focused on day-to-day engineering tasks rather than LeetCode-style puzzles.
Open permanent link

Evidence reviewed Nov 12, 2026. Reports can become stale.

Question groups

Topics

Independent and not affiliated with the companies represented. Collected material does not predict future interview questions.

2 questions

Every question has a public brief with the task, constraints, and follow-ups. Labels describe interactive practice access.

New public brief

Topic tags
Python
Data structures
Storage & state
Networking

xAICoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026

Token-Bucket State Transitions

Each subject has a token bucket stored in a shared key-value cache. A missing bucket begins full. Refill lazily when a request arrives: add elapsed_time * refill_rate, capped at capacity. If time has not advanc…

Practice focusAccept only when the refilled balance covers the full request, then subtract it. A rejected request spends nothing. Persist the refilled state in either case. A backward-moving clock must not create tokens. TokenBucket and the in-memory DistributedCache test double are provided. This base task is sequential; the cache name does not imply atomic distributed behavior. Refill returns a new bucket without editing its argument. Existing buckets retain their stored capacity/refill rate; call configuration initializes missing buckets only.…

Public brief

Topic tags
Python
Algorithms
Data structures
Storage & state
Networking

Coding exerciseCodingAI-generated

Runnable coding45 min

Reported interview periodN/A

Sliding-window rate limiter

Build a limiter, then add quota reporting, retry timing, and independent keys.

Practice focusPython, Queues, State, Boundary cases, Complexity through a runnable coding exercise.

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CANDIDATE-REPORTED · INDEPENDENT SYNTHESIS

What candidates report about the interview

3 reviewed signals

Use these reports to choose what to rehearse, not to predict a fixed loop. Formats vary by role, team, and date; confirm your current process with the recruiter. Frontier Rehearsal is independent and not company-endorsed.

Practice promptsOriginal exercises shaped by recurring preparation themes—not reported interview questions.1

Practice prompt (not a reported interview question): implement a small infrastructure-flavoured function with clear inputs and outputs, then compare your production-oriented solution with an algorithm-first alternative and justify which constraints matter most.
Open permanent link

Process signalsReported stages, formats, timing, and role-specific variations.2

According to candidate reports, xAI's 45-minute backend tech screen is a coding round that asks for something functional, such as an API endpoint or a data-processing function, with some architecture discussion but not a full system-design round.
Open permanent link
Candidate reports describe an xAI coding round delivered in Python and bash over about 45 minutes, focused on day-to-day engineering tasks rather than LeetCode-style puzzles.
Open permanent link

Evidence reviewed Nov 12, 2026. Reports can become stale.

Question groups

Topics

Independent and not affiliated with the companies represented. Collected material does not predict future interview questions.

2 questions

Every question has a public brief with the task, constraints, and follow-ups. Labels describe interactive practice access.

New public brief

Topic tags
Python
Data structures
Storage & state
Networking

xAICoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026

Token-Bucket State Transitions

Each subject has a token bucket stored in a shared key-value cache. A missing bucket begins full. Refill lazily when a request arrives: add elapsed_time * refill_rate, capped at capacity. If time has not advanc…

Practice focusAccept only when the refilled balance covers the full request, then subtract it. A rejected request spends nothing. Persist the refilled state in either case. A backward-moving clock must not create tokens. TokenBucket and the in-memory DistributedCache test double are provided. This base task is sequential; the cache name does not imply atomic distributed behavior. Refill returns a new bucket without editing its argument. Existing buckets retain their stored capacity/refill rate; call configuration initializes missing buckets only.…

Public brief

Topic tags
Python
Algorithms
Data structures
Storage & state
Networking

Coding exerciseCodingAI-generated

Runnable coding45 min

Reported interview periodN/A

Sliding-window rate limiter

Build a limiter, then add quota reporting, retry timing, and independent keys.

Practice focusPython, Queues, State, Boundary cases, Complexity through a runnable coding exercise.

xAI interview questions for engineering roles

xAI interview questions for engineering roles

What candidates report about the interview

Token-Bucket State Transitions

Sliding-window rate limiter

What candidates report about the interview

Token-Bucket State Transitions

Sliding-window rate limiter