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Question bank

Frontier AI technical interview question bank.

Practice coding, system design, behavioral, and project questions for frontier AI roles.

Company

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Frontier Rehearsal · Independent practice · Not affiliated with OpenAI, Anthropic, or xAI.

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Home
Question bank

Frontier AI technical interview question bank.

Practice coding, system design, behavioral, and project questions for frontier AI roles.

Company

FREE PRACTICE

Public demos, always pinned.

Start with either demo. They remain here when you filter or sort.

Free account: sign in to practice the marked Free questions.

Newest published questions; deterministic, never randomized.

Demo 1Number search with delayed feedback
Demo 2Design real-time device monitoring and control

Question bank filters

Reset filters

Question groups

Filter question bank by interview groupAll 40 Coding 36 System design 4 Behavioral 0 Hiring manager 0 Project deep dive 0

Topics

Filter question bank by topic tagsAll 269 Python 161 Algorithms 40 Data structures 46 Concurrency 27 Distributed systems 7 Storage & state 43 Networking 7 Reliability 30 ML / AI 27 Data / SQL 24 Security 7 Product design 25 Communication 66

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

34 questions

Sort question bankSortFree first Newest Oldest AI ratio ↓AI ratio ↑

Question bank results

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

Public brief

Topic tags
Python
Algorithms
Data / SQL

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Aug 2026

Anagrammed Substring Search

Given a text and a query, find the first position at which a substring of the text is an anagram of the query. Two strings are anagrams when they contain the same characters with the same multiplicities, regard…

Practice focusRequirements Implement: Return the zero-based start index of the first matching window, or -1 when no match exists. An empty query matches at index 0 ; a query longer than the text has no match. Characters are initially compared exactly, including case. Aim for O(n + m) time for a text of length n and query of length m , rather than sorting every window. Additional assessed interfaces 1. Return every matching start index. For an empty query, return every boundary from 0 through len(lookup string) . 2.…

Public brief

Topic tags
Python
Algorithms
Security

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Aug 2026

Delete a Position from Interval Coverage

A compact coverage set is represented by sorted, non-overlapping, non-touching inclusive intervals. If the covered values were expanded into one ordered sequence, delete the value at a given zero-based position…

Practice focusFor example, [(4, 7), (10, 11), (13, 15)] represents 4,5,6,7,10,11,13,14,15 . Deleting position 2 removes value 6 , producing [[4, 5], [7, 7], [10, 11], [13, 15]] . Requirements - Return intervals as [start, end] pairs. - Preserve sorted, non-overlapping, non-touching output. - A deletion may shrink an endpoint, remove a singleton interval, or split an interval in two. - Assume index refers to an existing covered value; state how you would report an invalid index. - Do not expand every covered integer when ranges may be large.…

Public brief

Topic tags
Python
Algorithms
Concurrency
Distributed systems
ML / AI

OpenAICodingHalf AI-generated

Python codingWebAssembly + public tests

Reported interview periodJul 2026–Aug 2026

Debug sharded matrix-multiplication gradients

Implement forward and backward matrix multiplication across world workers.

Practice focusSplit A evenly by rows, replicate B , compute each local A i @ B , and concatenate the local outputs in row order. For the backward pass, compute each local dA i = dY i @ B.T , concatenate the dA i blocks, and compute the global dB as the sum of A i.T @ dY i across workers. Return results that match an unsharded NumPy implementation. Validate matrix shapes and explain the communication required by the forward and backward passes. Follow-ups 1. Shard B instead and compare communication costs. 2. Add uneven row partitions and preserve output ordering. 3.…

Public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026

Tightest slice covering a character multiset

Find the shortest contiguous slice of a source string that contains every character of a required multiset with at least the required multiplicity, and return that slice.

Practice focusRequirements - Line 1 is the source string. Line 2 lists the required characters. - The chosen slice must be contiguous and must contain each required character at least as many times as it appears on line 2. - Compare slices by length. When several slices tie for the shortest length, return the one that begins earliest. - If no slice qualifies, return an empty string. - Matching is case-sensitive. - Return the slice itself, not its length and not its bounds. - run case(case: dict) forwards case["stdin"] to solve .…

New public brief

Topic tags
Python
Algorithms

ByteDanceCoding

Talk-through codingNo local grader

Reported interview periodNot available

Binary Search

Given a strictly increasing array of integers and a target, return the target's index or -1 when it is absent.

Practice focusThe solution must run in O(log n) time and use O(1) auxiliary space. An empty array returns -1 . Staged follow-ups 1. Return the first position where the target could be inserted while preserving order. 2. Support duplicate values by returning the first matching index. 3. Search a conceptually unbounded sorted data source through a bounded-access interface.

Public brief

Topic tags
Python
Algorithms

ByteDanceCoding

Talk-through codingNo local grader

Reported interview periodNot available

Palindrome Integer

Determine whether a signed 32-bit integer reads identically from left to right and right to left in decimal notation.

Practice focusNegative numbers are not palindromes because of the sign. A positive number ending in zero is not a palindrome unless the value itself is zero. Staged follow-ups 1. Solve without converting the number to a string. 2. Reverse only half the digits to avoid overflow and unnecessary work. 3. Generalize the check to an arbitrary base from 2 through 36.

Public brief

Topic tags
Python
Algorithms
ML / AI
Product design

Coding exerciseCodingAI-generated

Practice formatRunnable 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
Algorithms
Reliability

xAISystem designAI-generated

Practice formatWritten 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

Practice formatWritten 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

Practice formatWritten 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.

Previous2 of 2Next

Browse all original practice

Build a token-budget batcher
Sliding-window rate limiter
Interval calendar
Nested dictionary transforms
Command-log store
Dependency-ready scheduler
Streaming metric window
Evaluation slice aggregator
Build a reliable job runner
Build one adaptable decision story
Defend your role fit
Prepare one project deep dive
Design an evaluation artifact registry
Defend a reversible launch decision
Negotiate an ambiguous role scope
Trace a project from claim to evidence
Choose between two urgent priorities
Resolve a cross-functional disagreement
Own a consequential failure
Increase a team’s leverage
Warm a cold cache without a thundering herd
Ship a 500 GB checkpoint without a startup stampede
Make every document decision traceable to evidence
Share eight GPUs between two workloads with different promises
A mutable indexed sequence that must restart exactly
Trace a falling unit price to a rising bill
Keep a very long conversation usable while it streams
Design durable scheduled publishing
Make speculative code edits safe to accept
Recover a grouping rule from two-word phrases

CONTENT BOUNDARY

Independent frontier AI interview practice. Includes adaptations of collected interview material and original exercises; not official company questions and not affiliated with the companies represented. Collected material does not predict future interview questions. Report a correction.

Loading the question catalog…

FREE PRACTICE

Public demos, always pinned.

Start with either demo. They remain here when you filter or sort.

Free account: sign in to practice the marked Free questions.

Newest published questions; deterministic, never randomized.

Demo 1Number search with delayed feedback
Demo 2Design real-time device monitoring and control

Question bank filters

Reset filters

Question groups

Filter question bank by interview groupAll 40 Coding 36 System design 4 Behavioral 0 Hiring manager 0 Project deep dive 0

Topics

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

34 questions

Sort question bankSortFree first Newest Oldest AI ratio ↓AI ratio ↑

Question bank results

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

Public brief

Topic tags
Python
Algorithms
Data / SQL

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Aug 2026

Anagrammed Substring Search

Public brief

Topic tags
Python
Algorithms
Security

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Aug 2026

Delete a Position from Interval Coverage

Public brief

Topic tags
Python
Algorithms
Concurrency
Distributed systems
ML / AI

OpenAICodingHalf AI-generated

Python codingWebAssembly + public tests

Reported interview periodJul 2026–Aug 2026

Debug sharded matrix-multiplication gradients

Implement forward and backward matrix multiplication across world workers.

Public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026

Tightest slice covering a character multiset

Find the shortest contiguous slice of a source string that contains every character of a required multiset with at least the required multiplicity, and return that slice.

New public brief

Topic tags
Python
Algorithms

ByteDanceCoding

Talk-through codingNo local grader

Reported interview periodNot available

Binary Search

Given a strictly increasing array of integers and a target, return the target's index or -1 when it is absent.

Public brief

Topic tags
Python
Algorithms

ByteDanceCoding

Talk-through codingNo local grader

Reported interview periodNot available

Palindrome Integer

Determine whether a signed 32-bit integer reads identically from left to right and right to left in decimal notation.

Public brief

Topic tags
Python
Algorithms
ML / AI
Product design

Coding exerciseCodingAI-generated

Practice formatRunnable 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
Algorithms
Reliability

xAISystem designAI-generated

Practice formatWritten response45–60 min

Reported interview periodN/A

Recover a grouping rule from two-word phrases

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

Public brief

Topic tags
Python
Algorithms

Coding exerciseCoding

Practice formatWritten 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

Practice formatWritten 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.

Previous2 of 2Next

Browse all original practice

Build a token-budget batcher
Sliding-window rate limiter
Interval calendar
Nested dictionary transforms
Command-log store
Dependency-ready scheduler
Streaming metric window
Evaluation slice aggregator
Build a reliable job runner
Build one adaptable decision story
Defend your role fit
Prepare one project deep dive
Design an evaluation artifact registry
Defend a reversible launch decision
Negotiate an ambiguous role scope
Trace a project from claim to evidence
Choose between two urgent priorities
Resolve a cross-functional disagreement
Own a consequential failure
Increase a team’s leverage
Warm a cold cache without a thundering herd
Ship a 500 GB checkpoint without a startup stampede
Make every document decision traceable to evidence
Share eight GPUs between two workloads with different promises
A mutable indexed sequence that must restart exactly
Trace a falling unit price to a rising bill
Keep a very long conversation usable while it streams
Design durable scheduled publishing
Make speculative code edits safe to accept
Recover a grouping rule from two-word phrases

CONTENT BOUNDARY