Databricks Coding Interview Questions

Design and implement an in-memory key-value store class supporting put(key, value) and get(key) operations. Additionally, implement methods to track and return the…

Implement a firewall class (e.g., IpFirewall) that is initialized with an ordered list of rules, where each rule is a pair of…

You are commuting across a simplified map of San Francisco, represented as a 2D grid. Each cell is one of: 'S' (starting…

Design a SnapshotSet data structure supporting the following operations: - add(x): Add element x to the set. Returns whether it was newly…

Implement a generalized Tic-Tac-Toe game. The board is M×N (not necessarily 3×3 or square). A player wins by placing K consecutive marks…

You are given a special family of binary trees called Fibonacci trees. The k-th order Fibonacci tree T(k) is defined recursively: T(1)…

Implement a streaming encoder that compresses a sequence of 32-bit integers using two interleaved encoding strategies: Run-Length Encoding (RLE) and Bit-Packing (BP).…

Implement a thread-safe log writer (also called a 'system programming' or 'low-level coding' problem at Databricks). Multiple threads share a single logger…

Design and implement a customer revenue tracking system with the following operations: 1. insert(revenue: int) -> int: Add a new customer with…

Implement a LazyArray class that supports deferred (lazy) evaluation. The class wraps an array of integers and exposes two main operations: 1.…

Implement a function anagram_index(lookup, query) that returns the index of the first occurrence of an anagram of query as a consecutive substring…

You are given a collection of non-overlapping intervals (each represented as [start_idx, end_idx], possibly referring to substrings of a 'cipher' password string…

Implement a Circuit Breaker pattern in code. The circuit breaker wraps calls to an external service (simulated via a lambda/Supplier that returns…

Databricks phone screen coding problems in this category span several related forms: 1. House Robber (LC 198 base): Given an array of…

You are given three inputs: (1) a 2D array representing the game background/environment, which may contain pre-existing obstacle cells; (2) a 2D…

You are given a file system represented as a tree. There are two node types: - DirectoryNode: has a children list that…

Given n groups of nodes (e.g., [[1], [2,3], [4,5,6]]), each group is internally connected. You must connect all groups into a single…

Given a set of points on a 2D plane (or a 1D number line, depending on variant), remove all points that are…

You are given two strings: a reference string a and a source string b. Part 1: return the index pairs (intervals) of…

Given a dependency tree where tasks can be built concurrently, and each task takes equal time to build, identify 'bottlenecks' in the…

A coding problem requiring a Depth-First Search (DFS) solution. The candidate is expected to implement a standard DFS-based solution, then discuss and…

Design an ads marketplace system. Each advertiser account has a fund (balance). N ads providers submit bids (bidding mechanism is flexible); your…

A file system is represented as a tree with two node types: - DirectoryNode: has children (mix of DirectoryNode and FileNode) -…

Given a collection of elements (e.g., an array or string), return all possible permutations or combinations. This appeared as a follow-up to…

Implement a simplified JSON parser capable of parsing custom-formatted log files or handling strings containing escape characters. The parser should correctly handle…

You are given a data structure (a tree of nodes) representing a SQL query. Your task is to implement query optimizations on…

Given a 2D binary matrix filled with '0's and '1's, find the largest square submatrix that contains only '1's and return its…