How xAI Interviews in 2026: Process, Questions & What They Score

1. 01

   Design and implement a key-value store that supports SET, transactions (start, commit, abort), and nested transactions.

   Tests layered transaction state with rollback, so nested begin, commit and abort leave the store consistent.

2. 02

   Implement an LRU cache with GET and PUT operations.

   Tests O(1) get and put using a hash map with a doubly linked list, and clean class design under follow-ups.

3. 03

   Implement an iterator over a list with next, hasNext, getState, and setState.

   Tests stateful iterator design where getState and setState save and restore position without breaking next and hasNext.

4. 04

   Extend the iterator to support a list of iterators that behaves like one iterator, with a global state index.

   Tests composing iterators behind one interface while tracking a global index across them for state save and restore.

5. 05

   Read through a partially implemented LLM codebase and implement a missing function without test cases or specs.

   Tests reading unfamiliar code quickly and inferring a function's contract from its callers with no tests or spec.

6. 06

   Design a task management system with tasks broken into sub-tasks.

   Tests object-oriented modeling of tasks and sub-tasks as a tree with clear class boundaries and room for extensions.

7. 07

   Given unsorted logs of create, join, and leave events for Twitter Spaces, calculate the total active time per Space.

   Tests per-key event aggregation over unsorted logs, handling users who never leave, then scaling the computation.

8. 08

   Given an existing class that handles LLM input, implement token queueing: split the input into token sizes and return the resulting output queue.

   Tests extending an unfamiliar class to split input into token-sized chunks and build the output queue.

9. 09

   Add backup and restore to a key-value store with TTL expiry.

   Tests snapshot and restore of a store with TTL expiry, including how expiry times survive a restore.

10. 10

    Implement a word search over a grid (Word Search II).

    Tests a trie combined with depth-first search over a grid, pruning shared prefixes to avoid rescanning.

11. 11

    Solve a multi-level coding challenge and walk through how your structure changes as new requirements arrive.

    Tests incremental design: keeping earlier levels working while new requirements arrive without rewriting the structure.

12. 12

    Take-home: enhance X search through Grok using the Grok API.

    Tests shipping a working full-stack feature on the Grok API quickly and explaining the architecture in a demo.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Design and implement a rate limiter for a single URL, then extend it to support compound rules across multiple URLs and payload-aware limits.

   Tests rate-limiting algorithms such as sliding window or token bucket, extended to multi-URL rules and request-body size.

2. 02

   Design a distributed rate limiter for an API gateway handling 100k requests per second across multiple gateway instances.

   Tests distributed rate limiting at scale: shared counter storage, per-user and per-IP limits, and cross-node consistency.

3. 03

   Design a malware scanner reporting dashboard.

   Tests reporting-system design: ingesting scan results, aggregating them in storage, and serving a dashboard.

4. 04

   Design an inference batching system for a single GPU that maximizes utilization while users wait synchronously.

   Tests dynamic request batching on one GPU, trading utilization and throughput against synchronous user latency.

5. 05

   Design a file upload feature for an AI chat application.

   Tests upload pipeline design: chunked transfer, storage, scanning, size limits, and passing files to the model.

6. 06

   If you were building Grok chat, how would you secure it?

   Tests security design for a consumer AI service: authentication, abuse limits, data protection and prompt injection.

7. 07

   How would you prevent abuse and bot traffic on a consumer AI product?

   Tests layered abuse defenses: rate limits, bot detection, account and device signals, and cost controls.

8. 08

   How would you reduce perceived latency for the end user?

   Tests latency design for AI chat: streaming tokens, caching, and keeping slow work off the critical path.

9. 09

   What metrics would you track, and how would you monetize this feature?

   Tests product reasoning beyond architecture: choosing success metrics and a way to monetize the feature.

10. 10

    Design an LLM developer API with streaming, function calling, and rate limiting.

    Tests API design for LLM serving: streaming responses, function-calling schemas, and per-key rate limiting.

11. 11

    Design a real-time data ingestion pipeline for Grok from live X streams.

    Tests streaming ingestion design for live X data: low-latency pipelines, backpressure and ordering.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Why are you interested in working at xAI?

2. 02

   Tell me about your interest in AI.

3. 03

   What is the achievement or project you are most proud of?

4. 04

   Walk me through your technical background and the kind of work you focus on.

5. 05

   Is your background weighted toward backend or frontend?

6. 06

   Which area of xAI do you want to work in, and why?

7. 07

   Are you comfortable with xAI's work style and pace?

8. 08

   Tell me about your most challenging project, or the hardest technical challenge you have solved.

9. 09

   Tell me about a project you owned end to end.

1. 01

   Present a piece of exceptional work you have done and answer questions about it.