Databricks Software Engineer Interview Questions
Databricks Software Engineer interview questions focus on algorithmic coding and deeper systems problems that reflect real-world, data-intensive challenges. What’s distinctive about Databricks is the strong emphasis on distributed-systems thinking and performance: interviewers often probe Spark/Delta Lake concepts, cluster/resource tradeoffs, concurrency, and practical optimization rather than purely theoretical puzzles. Candidates are typically evaluated on problem-solving, code clarity and correctness, systems design for scale, debugging and performance reasoning, and communication skills that show how they collaborate across product and data teams. Effective interview preparation balances algorithm practice with hands-on distributed-systems experience. Expect a multi-stage process that usually begins with a recruiter screen and a timed coding assessment or technical phone screen, followed by deeper coding rounds, a system-design/architecture interview tailored to data platforms, and behavioral or hiring-manager conversations. Most interviews are virtual and use online IDEs. To prepare, do timed coding mocks, study distributed-systems fundamentals and Spark internals, build and optimize small ETL/Spark jobs, and craft concise STAR stories showing ownership and impact. During interviews, explain tradeoffs, write clear testable code, ask clarifying questions, and avoid undocumented assumptions.
Find path in implicit Fibonacci tree
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) is a single n...
Implement streaming RLE and bit-packed codec
You are implementing a simple compression scheme for sequences of 32‑bit signed integers. The codec should support two encoding strategies: 1. Run‑Len...
Design KV store with sliding-window average QPS
Problem Design an in-memory key–value store that supports mutation operations and can report the average QPS (queries per second) over a recent time w...
Implement a rate-limited hit counter
You are designing a hit counter that records the number of hits received in the past 5 minutes. Implement a class HitCounter with the following method...
Check if CIDR is fully canceled by rules
You are given: - A target CIDR block T as a string, e.g. "10.0.0.0/16". - A list of rule CIDR blocks. Each rule has: - A type: either "allow" or "de...
Implement run-length encoding and decoding
You are given a string consisting of lowercase English letters. You need to implement run-length encoding (RLE) and its corresponding decoding. 1. Enc...
Design a digital game shop backend
Design the backend for a simple digital game shop where users can buy virtual items (e.g., games, in‑game currency, skins) using credits in their acco...
Implement firewall matching with CIDR rules
Implement a simple IPv4 firewall rule matcher. Problem You are given an ordered list of firewall rules. Each rule has: - an action: ALLOW or DENY - a ...
Design Tic-Tac-Toe and QPS data structures
You are given two independent coding problems that focus on data structure and API design. --- Problem 1: Generalized Tic-Tac-Toe Game with Simple AI ...
Design a multithreaded event logger
Design a multithreaded in-memory event logger for a server application. Requirements: - Many worker threads running in the process need to log events ...
Implement RLE and bit-packing compression
You are asked to implement two related compression/decompression schemes: Run-Length Encoding (RLE) and bit-packing. --- Part 1 — Run-Length Encoding ...
Find optimal commute mode in a city graph
You are designing a route planner that suggests the best way to commute between two points in a city using different transportation modes. The city is...
Find first CIDR block covering IP
You are given: - A single IPv4 address as a string, e.g. "192.168.1.5". - A list of CIDR blocks (IPv4), each as a string in the form "a.b.c.d/x", wher...
Compute last-5-minute QPS in memory
Problem You are building a lightweight in-memory component that tracks the query load (QPS) of a service. Design a data structure with two operations:...
Implement a snapshotable set with iterators
Implement a SnapshotSet data structure with the following API: add(x), remove(x), contains(x), snapshot() -> sid, and iterate(sid) -> iterator over th...
Design a durable key-value store
System Design: Durable Key–Value Store Context Design a single-node, embeddable key–value store library with a simple API that must remain correct and...
Design a Slack-like messaging system
Design a Slack-like real-time team messaging system. Requirements: - Users can: - Create and join workspaces. - Create public and private channels...
Design KV store with sliding-window QPS metrics
Problem Design an in-memory key–value store that supports basic operations and can report the average operation load over a recent time window. Functi...
Find shortest path in a Fibonacci-ordered tree
You are given a recursively-defined binary tree T(order) whose shape depends only on order (not on node values). Nodes are labeled 0..N-1 using preord...
Design IP/CIDR rule matcher
Design and implement a rule matcher that returns 'accept' or 'deny' for a given IPv4 address based on a set of rules. Each rule can be either an inclu...