Waymo technical phone screen interview

Questions Waymo asks in this round 14

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  Shortest travel times from a start node to target nodesCodingA weighted graph models a road map. Given a start node and one or more target nodes, return the shortest travel time (an ETA) from the start to each target. Use Dijkstra's…

  Last asked Apr 2026Were you asked this too?
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  Is a vehicle ready to go after its maintenance events?CodingA vehicle can leave only when all its maintenance work is closed. Its log is a list of events: each opens a maintenance task of some type or ends the open task of that type…

  Last asked Sep 2026Were you asked this too?
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  Validate a parent-child forestCodingGiven a list of parent-child pairs, decide whether they form a valid forest: no node has two parents, there are no cycles, and every tree has one root. Return the reason when it…

  Last asked May 2026Were you asked this too?
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  Best meeting point on a gridCodingA grid marks several people's (or points') positions. Find the cell that minimizes the total distance to all of them. Start with a brute force (for example a BFS from each point)…

  Last asked May 2026Were you asked this too?
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  Decode stringCodingA string is encoded with the rule ktext, meaning text repeated k times; k is a positive integer that may have several digits, encoded parts can be nested, and plain letters can…

  Last asked May 2026Were you asked this too?
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  Island areas and water boundariesCodingYou are given an m x n grid of characters. Each cell is '1' (land) or '0' (water). Land cells that share a side (up, down, left or right) belong to the same island. Diagonal cells…

  Last asked Apr 2026Were you asked this too?
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  Maximum gapCodingGiven an unsorted array, return the largest difference between two neighbours in its sorted order, in linear time and space. The trick is bucket sort (pigeonhole): the maximum gap…

  Last asked Apr 2026Were you asked this too?
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  React Battleship boardCodingIn React, build the board for the game Battleship (just the board, no opponent logic). Each cell can be clicked to change its state (empty, hit, miss), and the board shows which…

  Last asked Apr 2026Were you asked this too?
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  Serialize an expression tree with the fewest parenthesesCodingGiven a binary expression tree of numbers and operators, print it as an infix expression using only the parentheses that precedence and associativity require (for example, keep…

  Last asked Feb 2026Were you asked this too?
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  Minimum knight movesCodingOn a chess board (possibly infinite), return the fewest moves a knight needs to get from one square to another. Use BFS, and consider symmetry or bidirectional BFS to make it…

  Last asked Feb 2026Were you asked this too?
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  Python fundamentals: a Fibonacci generator, a balanced BST and frozensetCodingA set of short Python tasks: write a generator that yields the Fibonacci sequence, build a balanced binary search tree (for example from a sorted list), and explain frozenset, how…

  Last asked Feb 2026Were you asked this too?
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  Sliding-window request rate limiterCodingImplement a rate limiter that accepts at most limit requests in any window of ttl milliseconds. - allow(timestamp) is called once per incoming request. timestamp is in…

  Last asked Jan 2026Were you asked this too?
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  Design large-scale model inference serving with back-of-envelope sizingAI systemDesign an inference system for a model used by 100 million daily active users. Do the back-of-envelope estimates for memory and bandwidth, then explain how you would reduce…

  Last asked Nov 2025Were you asked this too?
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  Model compression: quantization-aware training, distillation and moreML designExplain the main ways to make a model smaller and faster for deployment: quantization (post-training versus quantization-aware training), knowledge distillation and pruning. For…

  Last asked Nov 2025Were you asked this too?