OpenAI agentic coding (beta) interview

Questions OpenAI asks in this round 47

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  GPU credit ledger with out-of-order eventsCodingLockedBuild an in-memory ledger for GPU credits. Credit arrives as grants: each one has a unique id, an amount, and a time window in which it can be spent.

  Last asked Oct 2026Were you asked this too?
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  Social follow graph with point-in-time snapshotsCodingLockedBuild an in-memory follow graph that can answer questions about its own past.

  Last asked Oct 2026Were you asked this too?
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  Matrix product scan with autograd and a hand-written backwardCodingLockedYou get N square matrices A[0..N-1], each D x D. Compute every inclusive prefix product Y[i] = A[0] @ A[1] @ ... @ A[i] as you would inside an automatic-differentiation…

  Last asked Sep 2026Were you asked this too?
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  Vectorized nearest-neighbour classifier as a linear layerCodingLockedImplement a 1-nearest-neighbour classifier in NumPy with no Python loops: each test point gets the label of the closest training point by Euclidean distance. Then show that the…

  Last asked Sep 2026Were you asked this too?
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  Count and map a cluster tree with message passingCodingLockedA cluster of n machines is wired as a rooted tree (any number of children per node). Each machine knows only three things: its own id (a string such as "4"), its parent's id…

  Last asked Sep 2026Were you asked this too?
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  Turn-based monster team battle simulatorCodingLockedWrite a deterministic simulator for a turn-based battle between…

  Last asked Aug 2026Were you asked this too?
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  Data labeling scheduler with prefix-balanced modelsCodingLockedA data labeling platform pairs tasks, AI models and human annotators. IDs are 1-indexed strings: tasks "t1"…"t{totalTask}", models "m1"…"m{totalModel}", humans…

  Last asked Jul 2026Were you asked this too?
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  Fault-tolerant work queue with leases and retriesCodingLockedImplement an in-memory work queue that keeps working when workers crash. Workers take a task, process it, and report success or failure.

  Last asked Oct 2026Were you asked this too?
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  Persistent key-value store with binary snapshotsCodingLockedImplement an in-memory key-value store whose whole state can be saved…

  Last asked Oct 2026Were you asked this too?
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  Extensible chat app with command botsCodingLockedImplement an in-memory chat app with one shared channel that people and bots post to. Users send text.

  Last asked Oct 2026Were you asked this too?
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  IPv4 range iterator with reverse and CIDR supportCodingLockedAn IPv4 address such as "172.16.4.9" is four octets, each 0 to 255. Taken together, the octets form one unsigned 32-bit number.

  Last asked Sep 2026Were you asked this too?
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  Earliest release that supports a featureCodingYou ship a library whose releases are listed in versions, sorted from oldest to newest. Each entry is a "MAJOR.MINOR.PATCH" string; parts are non-negative integers and may be…

  Last asked Mar 2026Were you asked this too?
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  Per-user chat event counts in a sliding windowCodingLockedA chat service runs for months without restarting. It sends you a stream of message events.

  Last asked Oct 2026Were you asked this too?
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  Longest increasing subsequence of a price seriesCodingLockedYou get a series of financial values in time order: recorded prices, or monthly net profits, which may be zero or negative. Return the largest number of values you can pick…

  Last asked Oct 2026Were you asked this too?
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  Simplify a quadratic expressionCodingLockedYou get a string that is a sum of terms in any order. Each term is a constant, a multiple of x, or a multiple of x^2, with an optional sign and an optional integer coefficient.

  Last asked Oct 2026Were you asked this too?
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  Notification service with several bots per channelOO designLockedDesign the classes and interfaces for a notification service. A request names its recipients, the content and any of three channels: email, SMS and Slack.

  Last asked Oct 2026Were you asked this too?
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  Leaves left in a garden after wind gustsCodingLockedA rectangular garden is a grid where garden[r][c] is the number of leaves in that cell. Gusts are processed left to right; each gust (U, D, L or R) moves every remaining leaf one…

  Last asked Sep 2026Were you asked this too?
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  Typed task lock for mutually exclusive job typesCodingLockedSome jobs on a shared accelerator pool must not run alongside jobs of a different kind. Each job runs on its own thread and has one of two types: "gen" or "score".

  Last asked Sep 2026Were you asked this too?
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  Crash-safe on-disk key-value storeCodingLockedBuild a key-value store that keeps its data in files on the local disk and survives a crash at any moment: after a restart it must come back with every write it acknowledged, and…

  Last asked Sep 2026Were you asked this too?
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  Guess the number with one-call delayed feedbackCodingLockedA hidden integer secret lies in [1, n], inclusive. You can't read it.

  Last asked Sep 2026Were you asked this too?
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  Resumable iterators that save and restore their positionCodingLockedDesign an iterator that can save its position as a small, portable checkpoint and later be rebuilt from it, even in a new process, so iteration continues exactly where it…

  Last asked Jun 2026Were you asked this too?
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  In-memory SQL table with filtering and multi-key sortingCodingLockedBuild a small in-memory SQL-like database. You do not need to parse SQL text.

  Last asked Dec 2025Were you asked this too?
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  Temporal key-value store with point-in-time reads and restoreCodingLockedBuild an in-memory key-value store that keeps every version…

  Possibly retiredWere you asked this too?
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  Price a macaron order with set discountsCodingLockedA bakery sells macarons in at most five flavors, all at the same unit price. The baker packs an order into sets: a set holds at most one macaron of each flavor, and the baker…

  Last asked Oct 2026Were you asked this too?
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  Shortest path on a grid with a custom move setCodingLockedAn atom sits on a grid of allowed (.) and forbidden (#) cells and must reach a target cell. Instead of the usual four moves you get a list of actions, each a row and column offset.

  Last asked Oct 2026Were you asked this too?
• 

  Count ordered routes that visit one shop of each of four typesCodingLockedYou need four things from four kinds of shop: a bookshop (kind 0), a school-supply shop (1), a sports store (2) and a stationery store (3). The town has many shops of each kind…

  Last asked Oct 2026Were you asked this too?
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  Microorganisms eating neighbours: the largest survivorCodingLockedMicroorganisms stand in a row. Each has a family (one uppercase letter) and a size (a positive integer).

  Last asked Oct 2026Were you asked this too?
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  Mirror or blur a grayscale imageCodingLockedA grayscale image is a rectangular matrix of pixel values from 0 to 255. Given a filter code, return a new image.

  Last asked Sep 2026Were you asked this too?
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  Predict the winner of a pick-from-either-end gameCodingLockedTwo players play on a row of non-negative integers. They alternate, Player 1 first; on each turn the player takes either the leftmost or the rightmost remaining number and adds…

  Last asked Sep 2026Were you asked this too?
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  Fix one instruction so the robot reaches the targetCodingLockedA robot starts on S in a rectangular grid, facing up, and runs a program of commands: F moves one cell forward, B moves one cell backward without turning, and L and R turn in…

  Last asked Sep 2026Were you asked this too?
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  Largest all-ones square and rectangle in a binary matrixCodingLockedGiven a grid of 0s and 1s, return the area of the largest square that contains only 1s.

  Last asked Sep 2026Were you asked this too?
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  Mini spreadsheet with formulas and cycle detectionCodingLockedBuild a small in-memory spreadsheet. Cells are named by letters followed by digits, such as A1 or B10.

  Last asked Sep 2026Were you asked this too?
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  Event counter over a trailing 15-minute window with a ring bufferCodingLockedBuild an event counter for a monitoring system. It records events as they happen and answers how many happened in the last 15 minutes.

  Last asked Sep 2026Were you asked this too?
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  Memory allocator: leftmost free block and free by ownerCodingLockedA memory has n units, numbered 0 to n - 1, all free at the start. Process a list of operations in order; each one records exactly one value.

  Last asked Sep 2026Were you asked this too?
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  Text editor in stages: buffer, undo and redo, autocomplete, collaborationCodingLockedBuild the core of a text editor in four stages. Each stage builds on the one before, so keep the design easy to extend.

  Last asked Sep 2026Were you asked this too?
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  Snapshot set with frozen insertion-order iteratorsCodingLockedImplement SnapshotSet, a set of integers whose…

  Last asked Aug 2026Were you asked this too?
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  Count gears turning each way in a meshed gear train, or detect a jamCodingA mechanism has n gears numbered 0 to n - 1. Each connection u, v means gears u and v mesh, and every gear can be reached from gear 0 through connections. Gear 0 is driven…

  Last asked Mar 2026Were you asked this too?
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  Fewest tray rotations to eat a three-course mealCodingA round table has seats positions numbered clockwise from 0, and a customer sits at position customer. A rotating tray holds one dish slot in line with each seat; dishesi is the…

  Last asked Mar 2026Were you asked this too?
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  First meeting point of two digit-sum sequencesCodingStart from a positive integer and repeatedly add the sum of its decimal digits to get the next value: after 471 comes 471 + 4 + 7 + 1 = 483. Given the starting values of two such…

  Last asked Mar 2026Were you asked this too?
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  Simulate particles from a point source hitting a screenCodingA point source at (0, 0) fires particles at an infinitely tall vertical screen on the line x = 1. Each particle leaves at an angle theta drawn uniformly from (-pi/2, pi/2)…

  Last asked Feb 2026Were you asked this too?
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  Resolve a cd command to an absolute pathCodingLockedImplement the path logic of a shell's cd. Given the current directory and the argument to cd, return the absolute path pwd would print afterwards.

  Last asked Dec 2025Were you asked this too?
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  IP range to CIDR blocksCodingGiven a starting IPv4 address and a count n, return the shortest list of CIDR blocks that covers exactly the n consecutive addresses starting there, and no address outside that…

  Possibly retiredWere you asked this too?
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  Count identical islands in two gridsCodingYou get two binary grids of the same size. A region is a maximal group of 1 cells joined up, down, left or right. Two regions match when they contain exactly the same cell…

  Possibly retiredWere you asked this too?
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  Cross the most walls on a number line with limited energyCodingWalls stand at distinct non-zero integer points on an infinite number line. Wall k is at positionsk and costs costsk = 0 energy to cross. You start at 0 with energy units. Each…

  Possibly retiredWere you asked this too?
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  Largest square subgrid with every sum under a limitCodingYou get an integer grid and a limit maxsum. A side length k is valid when every contiguous k x k square in the grid sums to at most maxsum. Return the largest valid side length…

  Possibly retiredWere you asked this too?
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  Backpropagate through sort and divide by the medianCodingA function sorts a vector in ascending order and divides every sorted element by the median of the input: For example, f(3, 2, 1) = 0.5, 1.0, 1.5. Given the input x and the…

  Possibly retiredWere you asked this too?
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  Indexed sequence with checkpointsCodingLockedBuild a growable array that can take cheap snapshots. The spec arrives in three parts; finish and test each part before the next.

  Last asked Jul 2026Were you asked this too?