xAI interview questions for engineers

Topic tags
Algorithms
Product design

Reported interview periodNot available

Split matrix product

Compute the product of two matrices on a group of devices, two ways, and compare both results with a product computed on one device.

Practice focusRequirements - The device count divides both dimensions. One device is the local product. - Data-parallel: each device multiplies its row slice of the left matrix by the full right matrix and sends that block to rank zero, which stacks the rows. - Sharded: the left matrix is split by rows and the right matrix by columns. Over as many rounds as there are devices, each device passes its right-hand shard to the neighbor and adds that partial into the matching columns of the piece it keeps. - The communicator is a set of blocking queues.…

Public brief

Topic tags
Python
Algorithms
ML / AI
Product design

Coding exerciseCodingAI-generated

Runnable coding45–70 min

Reported interview periodN/A

Build a token-budget batcher

Implement a small batching primitive, then adapt it to padded cost, bounded output, and production reasoning.

Practice focusPython, Greedy algorithms, Boundary cases, ML batching, Complexity through a runnable coding exercise.

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.

Public brief

Topic tags
Python
Algorithms
Data structures
Product design
Communication

Coding exerciseCodingAI-generated

Runnable coding45 min

Reported interview periodN/A

Interval calendar

Reason about half-open intervals through conflicts, room counts, merging, and free slots.

Practice focusPython, Sorting, Intervals, Heaps, Edge cases through a runnable coding exercise.

Public brief

Topic tags
Algorithms
Reliability

xAISystem designAI-generated

Written response45–60 min

Reported interview periodN/A

Recover a grouping rule from two-word phrases

You get a short list of accepted two-word phrases and a batch of strings. Infer the rule that decides which strings belong together, implement it so the same input always yields the same partition, and say where the examples still underdetermine the answer.

Practice focusString algorithms, Specification recovery, Determinism, Edge-case analysis through a written response exercise.

Public brief

Topic tags
Python
Algorithms

Coding exerciseCoding

Written response35 minutes

Reported interview periodN/A

Vial log

Return the vials that stayed inside a temperature range for their whole stay.

Practice focusScanning, Missing data through a written response exercise.

Public brief

Topic tags
Python
Algorithms

Coding exerciseCoding

Written response35 minutes

Reported interview periodN/A

Comment batches

Collapse consecutive comments on the same path into one batch.

Practice focusOrder, Grouping through a written response exercise.

Public brief

Topic tags
Python
Algorithms
Data structures

Coding exerciseCoding

Written response40 minutes

Reported interview periodN/A

Launch order

Return one valid order of steps, or report a cycle.

Practice focusOrdering, Cycles through a written response exercise.

xAI interview questions for engineering roles

xAI interview questions for engineering roles

What candidates report about the interview

Split matrix product

Build a token-budget batcher

Sliding-window rate limiter

Interval calendar

Recover a grouping rule from two-word phrases

Vial log

Comment batches

Launch order

What candidates report about the interview

Split matrix product

Build a token-budget batcher

Sliding-window rate limiter

Interval calendar

Recover a grouping rule from two-word phrases

Vial log

Comment batches

Launch order