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Frontier AI technical interview question bank.

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

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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

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Filter question bank by interview groupAll 269 Coding 162 System design 48 Behavioral 29 Hiring manager 16 Project deep dive 14

Topics

Filter question bank by topic tagsAll 162 Python 161 Algorithms 36 Data structures 36 Concurrency 19 Distributed systems 7 Storage & state 23 Networking 6 Reliability 9 ML / AI 12 Data / SQL 17 Security 4 Product design 9 Communication 5

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

139 questions

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

Coding results

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

Free practice

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Palindrome after at most k deletions

Given a lowercase string and a deletion limit, decide whether removing at most that many characters can leave a palindrome while the surviving characters keep their order.

Practice focusRequirements - Line 1 is the string; line 2 is the integer limit. - Removing nothing is allowed, so a string that already reads the same in both directions always qualifies. - Each deletion is a single character, and characters that are kept never change position relative to each other. - On a mismatched pair, only two moves are worth trying: drop the left character or drop the right one. - Return true or false in lowercase, with no other text and no extra whitespace.…

Free practice

Topic tags
Python

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Words ordered by a custom alphabet

An ordering is supplied as a permutation of the letters. Decide whether the given word list is sorted according to that ordering.

Practice focusRequirements - Line 1 is the word count; that many words follow one per line; the final line is the ordering, a permutation of the twenty-six lowercase letters. - The final line is always the ordering, so the count line only says how many words precede it. - Compare adjacent words left to right and stop at the first position where the letters differ; the letter ranked earlier wins. - If one word is a proper prefix of the other, the shorter word must appear first. - Return true or false in lowercase, with no other text.…

Free practice

Topic tags
Python

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Segment text with a word list

Given a text and a small dictionary, decide whether the whole text can be written as a sequence of dictionary words, reusing a word as often as needed.

Practice focusRequirements - Line 1 is the text; line 2 is how many dictionary words follow, one per line. - Some inputs carry the two characters backslash and n instead of real line breaks; treat both forms as line separators before parsing. - Every character of the text must be covered in order by whole dictionary words; nothing may be skipped or reordered. - Words may be reused, and a word may be shorter than the remaining text but must match exactly at the current position. - Return true or false in lowercase, with no other text.…

New public brief

Topic tags
Python

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodSep 2026

Number search with delayed feedback

A hidden integer lies in the inclusive range 1..n, where n >= 1. The test fixture supplies a check(x) callback. Your code must not implement the callback and is not given the hidden integer.

Practice focusEach call to check(x) submits a new integer guess in 1..n , but returns the comparison result for the previous submitted guess: - the first call returns None ; - -1 means the previous guess was too high; - 0 means the previous guess was correct; and - 1 means the previous guess was too low. Implement: Return the hidden integer. The fixture validates the answer and permits at most 2 n.bit length() calls to check . Track which guess each delayed response describes; do not apply a response to the newly submitted guess.…

New public brief

Topic tags
Python
Algorithms
Data / SQL

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Implement 1-nearest-neighbor classification as a linear layer

You are given a matrix of labeled training examples and a batch of query examples. Implement squared-Euclidean 1-nearest-neighbor classification, then show that the same nearest-neighbor choice can be expressed…

Practice focusScenario You are given a matrix of labeled training examples and a batch of query examples. Implement squared-Euclidean 1-nearest-neighbor classification, then show that the same nearest-neighbor choice can be expressed as the output of an affine layer. For a query vector x and training vector x i : -||x - x i||² = 2x·x i - ||x i||² - ||x||² The final term is constant across all training examples for a fixed query, so it does not affect the winning index. This yields an affine score matrix with W = 2 X train.T and b i = -||x i||² .…

New public brief

Topic tags
Python
Algorithms

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Sep 2026

Infection Spread on a Grid

A grid contains healthy cells (0) and infected cells (1). Each day, infection spreads simultaneously from infected cells to their four orthogonal healthy neighbors. Return the number of days until every suscept…

Practice focusRequirements - All initially infected cells spread at the same time. - Return 0 when no healthy cell exists initially. - Do not allow newly infected cells to spread again during the same day. - Handle empty grids and validate rectangular input. - Target O(rows cols) time and space proportional to the active frontier. In the second stage, cells marked 2 are immune: they never change and block propagation. Follow-ups 1. Add recovery after a configurable number of days. 2. Require at least q infected neighbors before a cell changes. 3.…

New public brief

Topic tags
Python
Data structures

OpenAICodingHalf AI-generated

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Aggregate Labels from Noisy Annotators

You receive labels from multiple annotators, with missing entries. Infer one binary label per item, identify annotators who systematically disagree with their peers, remove them, and recompute the labels.

Practice focusAssumptions Rows are annotators, columns are items, labels are 0 , 1 , or -1 for missing. Majority ignores missing entries and ties resolve to 1 . An annotator is bad when agreement with provisional labels on overlapping items is strictly below 0.5 . If gold is supplied, also return accuracy rounded to a stated precision. Requirements - Define behavior for items with no labels and annotators with no overlap. - Avoid treating missing values as votes. - Recompute the final majority after filtering. - State complexity and numerical representation.…

Public brief

Topic tags
Algorithms

OpenAICodingAI-generated

Talk-through codingNo local grader

Reported interview periodSep 2026

Deal and rank three-card poker hands

Implement the core of a three-card poker game. Cards are dealt to seated players one card at a time over three passes, then every hand is ranked and the winner or winners are returned.

Practice focusScenario Implement the core of a three-card poker game. Cards are dealt to seated players one card at a time over three passes, then every hand is ranked and the winner or winners are returned. Ranks increase from 2 through A . A deck contains one card for every rank and suit combination, and a card may be dealt at most once. Assumed interface The exact public API is intentionally flexible. One coherent option is: State any alternative interface before implementation.…

Public brief

Topic tags
Python

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Sep 2026

Expiring compute-credit ledger

Implement a ledger for compute-credit grants and debits whose events may arrive out of order.

Practice focusEach grant has a unique ID, amount, activation timestamp, and expiration duration. A grant is available through its expiration boundary. subtract(amount, timestamp) consumes credits that expire soonest. get balance(timestamp) returns the balance that would have been available at that point in time by evaluating all applicable events in chronological order. Define deterministic behavior for duplicate IDs, insufficient balance, equal timestamps, and late-arriving events. Preserve enough history to answer past-balance queries correctly. Follow-ups 1.…

Public brief

Topic tags
Python
Data structures
Concurrency
Networking

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodFeb 2026–Sep 2026

IPv4 and CIDR Iterator

Implement an iterator that walks IPv4 addresses from a seed, either forward, backward, or within the seed's CIDR block.

Practice focusRequirements - Accept a plain IPv4 address or CIDR such as 10.2.3.4/24 . - Include the seed as the first result. - Forward iteration ends at 255.255.255.255 or the block broadcast address. - Backward iteration ends at 0.0.0.0 or the block network address. - Validate octets, prefix lengths, and direction; raise StopIteration after exhaustion. - Use integer address arithmetic rather than incrementing dotted components as strings. State whether network and broadcast addresses are included; for this problem, include both boundaries. Follow-ups 1.…

New public brief

Topic tags
Python

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodDec 2025–Sep 2026

Generalized Tic-Tac-Toe

Implement a two-player game on a rows x cols board. A player wins by placing k consecutive marks horizontally, vertically, or along either diagonal.

Practice focusRequirements - Player 1 moves first and players alternate. - move places the current player's mark and returns that player number if the move completes a run of length k ; otherwise return 0 . - After a win, later calls return the existing winner without changing it. - Initially assume coordinates are valid and empty; explain how production code would reject invalid moves. - Support rectangular boards and k smaller than either dimension. - Avoid scanning the entire board after every move.…

New public brief

Topic tags
Python

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Sep 2026

Revenue Tracking with Direct Referrals

Build a customer revenue index. Each inserted customer has personal revenue and may name an existing customer as a referrer. A customer's total revenue is personal revenue plus the personal revenue of direct re…

Practice focusRequirements - Assign IDs starting at 0 in insertion order. - If a referrer is provided, update that customer's total by the new customer's personal revenue. - A customer's referrals do not contribute to its referrer's total; attribution is one level only. - The query considers totals at least min total revenue , orders by (total revenue, id) , and returns at most k IDs. - Validate non-negative revenue, valid referrers, and non-negative k .…

New public brief

Topic tags
Python

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodMar 2026–Sep 2026

Evaluate an arithmetic string

Write solve(raw: str) -> str that evaluates one arithmetic expression and returns its integer value as text.

Practice focusRequirements - The expression contains non-negative integers, single spaces, and the operators + , - , , and / . There are no parentheses, no unary minus, and no exponentiation. - and / bind more tightly than + and - ; work left to right inside each precedence level. - / is integer division that truncates toward zero, so -3/2 truncates to -1 if a lead-in subtraction makes the intermediate negative. - Ignore every space and read the run of digits between operators as one number.…

Public brief

Topic tags
Python
ML / AI

OpenAICodingHalf AI-generated

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Sep 2026

Debug a minimal transformer computation

A small NumPy model produces incorrect attention outputs and fails to learn. Implement corrected versions of four operations used by a decoder-style model. The model dimension is small and attention uses one he…

Practice focusScenario A small NumPy model produces incorrect attention outputs and fails to learn. Implement corrected versions of four operations used by a decoder-style model. The model dimension is small and attention uses one head, so focus on tensor semantics rather than framework APIs. Interface Requirements pos embed Return token representations with positional embeddings added elementwise. Shapes must match or broadcast unambiguously. attention - Compute scaled dot-product attention using a scale of 1 / sqrt(d k) .…

New public brief

Topic tags
Python
Data structures
Security

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Sep 2026

Minimize Encryption Work in a File Tree

A file hierarchy contains directories and files. Some files are already encrypted. You may encrypt an individual file or issue one recursive encryption request for an entire directory. Choose operations with mi…

Practice focusRequirements and cost model - Encrypting one file costs t req + t file . - Encrypting a directory costs t req + N t file , where N is every file in its subtree, including already-encrypted files. - A subtree with no unencrypted files costs 0 . - At a directory, you may batch the whole subtree or solve its children independently. count files returns (encrypted count, unencrypted count) . The input is a finite tree of FileNode and DirectoryNode objects, with boolean encryption flags, no cycles or shared nodes, and non-negative integer costs.…

Public brief

Topic tags
Python
Data structures
Distributed systems

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodOct 2025–Sep 2026

Aggregate Count and Topology over a Machine Tree

Machines form a rooted tree and may communicate only with their parent or children. Implement message handling so the root can count all machines and reconstruct a deterministic topology string.

Practice focusRequirements - A count request propagates to children; a leaf replies 1 ; an internal node replies with one plus all child counts. - A topology request produces id(child1,child2,...) ; a leaf is id[] . - Only the root publishes the final result. - Correlate replies with operation type and wait for every expected child exactly once. - Do not assume child replies arrive in order; sort by child ID for deterministic topology. - Avoid blocking the message handler and state behavior for duplicate requests.…

New public brief

Topic tags
Python
Algorithms

GoogleCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Contagion in a Grid

A rectangular grid contains empty cells (0), fresh items (1), and contaminated items (2). At each minute, every fresh item sharing an edge with a contaminated item becomes contaminated. All changes within a min…

Practice focusImplement: Return the number of minutes required for every fresh item to become contaminated. Return 0 if there are no fresh items initially, and -1 if at least one fresh item is unreachable. Diagonal neighbors do not interact. Aim for O(rows columns) time and space. Staged follow-ups 1. Return the earliest arrival time for every reachable cell from multiple sources. 2. Introduce blocked cells and targets, returning the time when all targets are reached. 3. You may remove at most one shared blocker for the entire propagation.…

New public brief

Topic tags
Python
Algorithms
Concurrency

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Shortest maze route with collected keys

Guide a walker from the start cell to the exit of a character grid, where locked doors stay shut until the matching key has been picked up, and report the fewest single-cell moves needed.

Practice focusRequirements - Line 1 gives rows cols . The next rows lines each contain exactly cols characters. - . is open floor, blocks movement, S is the start, and E is the exit. - Lowercase letters a through f are keys. Uppercase A through F are doors that require the key with the same letter. - E marks the exit and is never read as the door for key e . - A collected key is kept permanently, so the walker may revisit a cell with a different set of keys. - Each move changes the row or column by one. Entering a door without its key is not allowed.…

New public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Stamp a supplied route onto a grid

Mark the open floor cells named in a coordinate list and return the resulting grid, leaving walls, the start, and the exit exactly as they were.

Practice focusRequirements - Line 1 is rows cols . The next rows lines are the grid, each exactly cols characters long. - A count follows the grid, then that many lines of row col . - Coordinates are zero-based and name the row first, then the column. - Replace a . at a listed coordinate with . If the cell holds S , E , , or is already , leave it unchanged. - Listing the same coordinate again has no additional effect. - Return the whole grid with each row on its own line, rows separated by a newline, and no extra text. - Every coordinate is inside the grid.…

New public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Shortest route through directional cells

Compute the fewest orthogonal moves from the start to the exit of a grid containing cells that can only be entered while travelling in one particular direction.

Practice focusRequirements - Line 1 gives rows cols . The next rows lines each contain exactly cols characters. - is a wall, S is the start, and E is the exit. - can be entered only by moving right into it. < can be entered only by moving left into it. - The restriction applies when entering a directional cell. Once inside, the walker may leave in any direction. - S , E , and ordinary open cells accept entry from any side. - Each move goes one cell up, down, left, or right and costs one step.…

New public brief

Topic tags
Python

GoogleCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Sep 2026

Compute File-System Size

A file-system node is either a file with a non-negative byte size or a directory containing child nodes. Hard links are possible, so the same node object may be reachable by more than one path and cycles may ex…

Practice focusImplement: Return the sum of the sizes of all distinct reachable files. Count a node at most once even if multiple paths reference it. An empty directory has size 0 . You may identify nodes by stable object identity. Aim for O(V + E) time and O(V) auxiliary space, where V is the number of distinct reachable nodes and E is the number of child references. Staged follow-ups 1. Provide an iterative traversal for inputs too deep for recursion. 2. Add memoization for repeated directory-size queries. 3.…

New public brief

Topic tags
Python
Algorithms
Concurrency

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Aug 2026

Choose the Best Transit Mode Through a Grid

A grid contains a start S, a destination D, blocked cells, and cells labeled by transit mode. A trip must use one mode for its entire route. Choose the reachable mode with the best travel time and cost.

Practice focusRequirements - Digit '1' identifies modes[0] , digit '2' identifies modes[1] , and so on. - Movement is allowed in four cardinal directions through cells of the chosen digit. - S and D may be entered for free and add neither time nor cost. - X , unrelated mode digits, and any other symbols are blocked. - For a route using mode i , each mode cell contributes times[i] and costs[i] . - Choose minimum total time, then minimum total cost, then earlier position in modes . Return "" if no mode reaches D .…

New public brief

Topic tags
Python
Algorithms

GoogleCoding

Python codingWebAssembly + public tests

Reported interview periodDec 2025–Aug 2026

Islands in a Dynamic Grid

You are given a rectangular binary grid. 1 represents land and 0 represents water. Cells belong to the same island when they share an edge; diagonal contact does not connect islands.

Practice focusFirst implement: Then support a grid that begins as all water. After each (row, column) operation, turn that cell into land and report the current island count: Adding an already-land cell leaves the count unchanged. Assume coordinates are in bounds. Staged follow-ups 1. Compare DFS, BFS, and disjoint-set solutions for the static problem. 2. Achieve near-constant amortized work per addition with union by rank and path compression. 3. Discuss the harder case in which land can also be removed.

Public brief

Topic tags
Python
Algorithms
Concurrency
Product design

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodFeb 2026–Aug 2026

Parallel Prefix Matrix Products with Autograd

Given square matrices W[0..n-1], compute inclusive prefix products P[i] = W[0] @ ... @ W[i] using a Hillis–Steele doubling scan, then implement the backward pass without relying on an automatic-differentiation …

Practice focusRequirements - weights has shape (n, d, d) ; return prefixes with the same shape. - Each scan round combines entries 2 r positions apart, using out-of-place round updates so values from one round are not mixed with the next. - Backward returns the gradient for every input matrix for an arbitrary gradient on every prefix. - Handle n=0 , n=1 , non-commutativity, and floating-point dtype consistently. - Explain saved intermediates and complexity in sequential work, parallel depth, and memory. Follow-ups 1.…

Previous3 of 6Next

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 269 Coding 162 System design 48 Behavioral 29 Hiring manager 16 Project deep dive 14

Topics

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

139 questions

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

Coding results

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

Free practice

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Palindrome after at most k deletions

Given a lowercase string and a deletion limit, decide whether removing at most that many characters can leave a palindrome while the surviving characters keep their order.

Free practice

Topic tags
Python

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Words ordered by a custom alphabet

An ordering is supplied as a permutation of the letters. Decide whether the given word list is sorted according to that ordering.

Free practice

Topic tags
Python

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Segment text with a word list

Given a text and a small dictionary, decide whether the whole text can be written as a sequence of dictionary words, reusing a word as often as needed.

New public brief

Topic tags
Python

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodSep 2026

Number search with delayed feedback

A hidden integer lies in the inclusive range 1..n, where n >= 1. The test fixture supplies a check(x) callback. Your code must not implement the callback and is not given the hidden integer.

New public brief

Topic tags
Python
Algorithms
Data / SQL

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Implement 1-nearest-neighbor classification as a linear layer

New public brief

Topic tags
Python
Algorithms

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Sep 2026

Infection Spread on a Grid

New public brief

Topic tags
Python
Data structures

OpenAICodingHalf AI-generated

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Aggregate Labels from Noisy Annotators

Public brief

Topic tags
Algorithms

OpenAICodingAI-generated

Talk-through codingNo local grader

Reported interview periodSep 2026

Deal and rank three-card poker hands

Implement the core of a three-card poker game. Cards are dealt to seated players one card at a time over three passes, then every hand is ranked and the winner or winners are returned.

Public brief

Topic tags
Python

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Sep 2026

Expiring compute-credit ledger

Implement a ledger for compute-credit grants and debits whose events may arrive out of order.

Public brief

Topic tags
Python
Data structures
Concurrency
Networking

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodFeb 2026–Sep 2026

IPv4 and CIDR Iterator

Implement an iterator that walks IPv4 addresses from a seed, either forward, backward, or within the seed's CIDR block.

New public brief

Topic tags
Python

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodDec 2025–Sep 2026

Generalized Tic-Tac-Toe

Implement a two-player game on a rows x cols board. A player wins by placing k consecutive marks horizontally, vertically, or along either diagonal.

New public brief

Topic tags
Python

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Sep 2026

Revenue Tracking with Direct Referrals

New public brief

Topic tags
Python

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodMar 2026–Sep 2026

Evaluate an arithmetic string

Write solve(raw: str) -> str that evaluates one arithmetic expression and returns its integer value as text.

Public brief

Topic tags
Python
ML / AI

OpenAICodingHalf AI-generated

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Sep 2026

Debug a minimal transformer computation

New public brief

Topic tags
Python
Data structures
Security

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Sep 2026

Minimize Encryption Work in a File Tree

Public brief

Topic tags
Python
Data structures
Distributed systems

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodOct 2025–Sep 2026

Aggregate Count and Topology over a Machine Tree

Machines form a rooted tree and may communicate only with their parent or children. Implement message handling so the root can count all machines and reconstruct a deterministic topology string.

New public brief

Topic tags
Python
Algorithms

GoogleCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Contagion in a Grid

New public brief

Topic tags
Python
Algorithms
Concurrency

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Shortest maze route with collected keys

Guide a walker from the start cell to the exit of a character grid, where locked doors stay shut until the matching key has been picked up, and report the fewest single-cell moves needed.

New public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Stamp a supplied route onto a grid

Mark the open floor cells named in a coordinate list and return the resulting grid, leaving walls, the start, and the exit exactly as they were.

New public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Shortest route through directional cells

Compute the fewest orthogonal moves from the start to the exit of a grid containing cells that can only be entered while travelling in one particular direction.

New public brief

Topic tags
Python

GoogleCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026–Sep 2026

Compute File-System Size

New public brief

Topic tags
Python
Algorithms
Concurrency

DatabricksCoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Aug 2026

Choose the Best Transit Mode Through a Grid

New public brief

Topic tags
Python
Algorithms

GoogleCoding

Python codingWebAssembly + public tests

Reported interview periodDec 2025–Aug 2026

Islands in a Dynamic Grid

You are given a rectangular binary grid. 1 represents land and 0 represents water. Cells belong to the same island when they share an edge; diagonal contact does not connect islands.

Public brief

Topic tags
Python
Algorithms
Concurrency
Product design

OpenAICoding

Python codingWebAssembly + public tests

Reported interview periodFeb 2026–Aug 2026

Parallel Prefix Matrix Products with Autograd

Previous3 of 6Next

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