Waymo Software Engineer
Interview Guide

Implement a multi-source Breadth-First Search (BFS) algorithm to randomly populate an $m \times n$ grid with distinct tokens while ensuring each token group remains contiguous.

Write an algorithm to traverse a 2D matrix, calculate recursive cell weights, and return optimized path parameters under strict time constraints.

Solve a string dynamic programming problem focused on pattern matching and sequence alignment.

Given a buggy implementation of a history buffer in C++, identify memory leaks, race conditions, and syntax errors, then refactor it for production stability.

Given a set of node coordinates and connectivity requirements, traverse a graph structure using suitable graph algorithms to process dynamic spatial data.

Describe how you approach framing an open-ended, ambiguous real-world scenario into a well-defined engineering problem.

resource carries version INT NOT NULL DEFAULT 1. resource_revision holds revision_id, resource_id, version, actor_user_id, change_kind, patch JSONB, request_id, created_at with UNIQUE (resource_id, version). outbox_event holds aggregate_type, aggregate_id, aggregate_version, event_type, payload, status. A PUT carries the version the client read. Write the exact statements for the single transaction that applies the edit, records the revision and enqueues 'resource.updated', and give the handler's branch on zero affected rows. Then say what PostgreSQL 16 does under READ COMMITTED when two of these updates hit one row at once.

resource_tag is (resource_id, tag_id) with PK (resource_id, tag_id); resource_share is (resource_id, shared_with_user_id, permission). The tagged-and-shared listing inner-joins resource to both, filters tenant_id, tag_id = ANY($2) and shared_with_user_id = $3, orders by updated_at DESC and takes 50. Pages come back with fewer than 50 distinct resources and the total in the header is far too high. Explain the row multiplication, rewrite both the page query and the count query so each is correct, and name the index each one needs. PostgreSQL 16.

Design a high-throughput, low-latency distributed inference platform capable of hosting both internal deep learning models and large language models (LLMs) for bulk evaluation.

Architect a real-time telematics data pipeline to handle continuous sensor logging, vehicle state telemetry, and over-the-air (OTA) updates for a large autonomous fleet.

Design an object-oriented system for differential scene evaluation or autonomous scenario generation.

Build a scalable data annotation and labeling infrastructure that ingests multi-modal sensor streams and distributes task processing to human-in-the-loop workforces.

Design an API server and web backend to monitor real-time vehicle supply and depot logistics for autonomous fleet operations.

Explain the mathematical and structural trade-offs between classification and regression loss functions when modeling agent trajectory prediction.

Implement geometric computer vision concepts in C++, such as vector cross products and nearest-neighbor point cloud searching algorithms.

Walk through the end-to-end design of a machine learning active learning pipeline, detailing how hard cases are selected, labeled, and used for model fine-tuning.

Solve a physics-based vehicle kinematics problem: given a vehicle traveling at velocity $x$ on a surface with friction coefficient $y$, calculate the exact stopping distance and braking threshold.

Walk through a complex technical project you led from initial design through production deployment, highlighting key architecture decisions and trade-offs.

Search results for a subset of tenants are hours stale; the rest are current. The projection consumer reports lag of zero on 15 of 16 partitions and 400,000 on one. Its error rate is flat and its CPU is idle. outbox_event has no pending rows older than a second, so the relay has published everything it holds. Identify the mechanism, give the ordered checks, and state what you do in the first ten minutes versus what you change permanently.