Databricks interview notes, page 17 of 22

Large Enterprises

Most of these Databricks write-ups come from Software Engineers (192), then Machine Learning Engineers (9) and Data Scientists (8). The most reported rounds are the technical phone screen (136), the system design round (57), the behavioral / leadership round (9) and the onsite coding round (6).

216 interview notes · updated Jul 2026

Databricks·Software Engineer·Technical Phone Screen

Jun 2026

Databricks SWE interview with a coding round focused on a QPS tracking problem. The core question was straightforward enough but the follow-ups on memory optimization are where things got interesting and where I felt a bit underprepared.

Design an in-memory data structure with a record(timestamp) method and a getQPS(timestamp) method, where getQPS returns the average requests per second over the last 5 minutes ending at the given timestamp.
How would you implement this using a sliding window approach?
How would you reduce memory usage if you can't store every individual request timestamp, while still keeping performance reasonable?

“My first instinct was to just store every timestamp in a list and filter on getQPS.”

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Databricks·Software Engineer·Technical Phone Screen

Jun 2026

Databricks software engineering interview that went deep on fault tolerance patterns. The main problem was a double-layer circuit breaker and it was more involved than I expected, especially around getting the state transitions right under mixed failure sequences.

Design and implement a double-layer circuit breaker that wraps calls to multiple backend servers, including the full state machine (Closed, Open, Half-Open), a `call(server_lambda)` wrapper API, and a demonstration of behavior across mixed success and failure sequences.

“The state machine part felt manageable at first.”

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Databricks·Software Engineer·Technical Phone Screen

Jun 2026

Databricks software engineering interview with a networking/systems coding problem. The main question was building an IPv4 firewall rule matcher, with a few follow-ups that got progressively more involved. Felt like a solid mid-to-senior level technical screen.

Implement a function that takes an ordered list of firewall rules (each with an ALLOW/DENY action and a CIDR prefix) and an IPv4 address string, and returns whether the IP is allowed. Rules are evaluated in order and the first match wins; default is DENY.
What test cases would you use to validate your firewall matcher implementation?
Extend the API so that instead of checking a single IP, the input is itself a CIDR block. Define what the return value should represent and how to handle cases where the range partially overlaps multiple rules with different actions.
Formally specify, using 32-bit integer arithmetic and bitwise operations, the exact condition under which an IPv4 address matches a given CIDR network and prefix length.

“More involved than it looks at first glance.”

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Databricks·Data Scientist·Technical Phone Screen

Jun 2026

SQL question for a Data Scientist role at Databricks, graph-style problem dressed up as a simple following table. One question, pretty focused, no fluff.

Given a table of YouTuber-follower relationships, write a SQL query that returns the count of distinct second-degree followers for each YouTuber, excluding anyone who already follows them directly and excluding the YouTuber themselves.

“I knew immediately it was a self-join situation but tripped up on the exclusion logic.”

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Databricks·Software Engineer·Technical Phone Screen

Jun 2026

Databricks software engineer interview with a meaty algorithmic question about game tree search. The whole thing was one deep technical problem and they really wanted you to think through the complexity tradeoffs carefully.

Given an n×n board game (like Tic-Tac-Toe) with a configurable win condition k, design an algorithm using BFS over game states to determine if the current player can force a win within at most t moves. Cover state representation, successor generation, win/draw detection, avoiding revisited states, pruning heuristics, and analyze worst-case time and space complexity in terms of n, k, t, and branching factor. Also give complexities for the standard 3×3, k=3 case.

“This was a lot to hold in your head at once.”

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Databricks·Software Engineer·Onsite - System Design / Architecture

Jun 2026

Databricks SWE interview with a system design question around a book marketplace. The API design piece was more demanding than I expected, they really pushed back on anything that felt like lazy field additions.

Design a system for buying and selling books. How would you handle it at scale, and walk through your API design decisions?

“The part that tripped me up was the API design.”

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Databricks·Software Engineer·Technical Phone Screen

Jun 2026

Round 2 at Databricks was a grid traversal problem with a bunch of layers stacked on top. The base case was manageable but the follow-ups kept coming and I had to describe a Dijkstra approach under pressure without actually coding it.

Given a 2D grid with a start, destination, obstacles, and cells labeled with transportation modes (walk, bike, car, train), each mode having its own cost and time arrays, find the fastest single-mode path from start to destination. Break ties by cheapest cost. Only horizontal and vertical movement allowed.
Follow-up: modify the solution to allow switching transportation modes mid-path, with a penalty applied per switch. Then further constrain the number of allowed switches.

“The base version is pretty approachable.”

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Databricks·Software Engineer·Technical Phone Screen

Jun 2026

Interviewed for a data engineer role at Databricks and got asked about foundational data architecture concepts. Short post, just the one question worth sharing.

Can you explain what a Medallion Architecture is?

“Pretty standard for a Databricks interview honestly.”

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Databricks·Software Engineer·Hiring Manager Screen

Jun 2026

Went through a screen for a Software Engineer role at Databricks, mostly behavioral and motivational stuff. Nothing too technical but the level and promotion questions were a bit unexpected.

Tell me about yourself.
What is the most significant project you have worked on?
Why are you looking to leave your current role?
Why Databricks specifically?
What is your current seniority level, what level would you be joining at, and how long did it take you to get promoted through each level?

“Standard opener, rattled through my background without much thought.”

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Databricks·Software Engineer·Technical Phone Screen

Jun 2026

Databricks SWE interview with a graph/grid traversal problem that had a twist I didn't see coming. The multi-modal cost-vs-time tiebreaker made it more interesting than a plain shortest path question.

Given a city grid with multiple transportation modes, each having their own cost and time matrices, find the fastest route from a source cell to a destination. If two modes arrive at the same time, pick the cheaper one.

“My first instinct was modified Dijkstra and that was right, but I fumbled the tiebreaker logic for a bit.”

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