Atlassian Interview Questions — Page 10

Atlassian·Machine Learning Engineer·Onsite - System Design / Architecture

Jul 2026

Atlassian ML Engineer interview focused almost entirely on designing a recommendation system for a product feed. It was a deep system design session and they really wanted to see you hold the whole pipeline in your head at once, from retrieval to serving to how you'd know if it's actually working.

Design a recommendation system for a product feed (like an e-commerce home feed). Walk through the full system including requirements, architecture, and how you'd evaluate it.
How would you handle cold start for new users and new items in this recommendation system?
What offline metrics would you use to evaluate the ranker, and how do they connect to what you actually care about in production?
How would you design the feature store and training pipeline to keep features fresh enough for a real-time feed?
How do you prevent feedback loops and ensure diversity in the recommendations over time?

“This was the whole interview basically.”

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Atlassian·Data Scientist·Technical Phone Screen

Jul 2026

Atlassian Data Scientist interview with a pretty brutal algorithmic question that felt more like a competitive programming contest than anything I'd call data science. One question, lots of depth required, and I'm still not sure I nailed the proof parts.

Given an array of n integers and an integer k, place k cluster centers on the real line to minimize the maximum L1 distance from any point to its nearest center. Design an algorithm faster than O(nk), prove correctness, handle large coordinates, and reconstruct the actual center positions.

“This one hit different.”

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Atlassian·Software Engineer·Technical Phone Screen

Jul 2026

Atlassian software engineer interview with a grid-based word search problem. Pretty standard algorithmic round but the complexity discussion was where things got interesting.

Given an m x n character grid and a target word, can the word be found by moving through horizontally or vertically adjacent cells without reusing any cell? Walk through your approach and analyze the time and space complexity.

“DFS with backtracking was the obvious move here and I got there pretty quickly.”

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Atlassian·Machine Learning Engineer·Onsite - System Design / Architecture

Jul 2026

ML system design round at Atlassian for an MLE role. The whole session was one extended design question about building search for a product like Jira or Confluence, and they expected you to go pretty deep on almost every layer of the stack.

Design a search system for one of Atlassian's products, such as Jira issues or Confluence pages. Walk through the full stack from indexing to ranking to serving.
How would you build the indexing pipeline to handle continuous updates and deletes for documents at the scale of tens of millions?
What embedding model would you choose for semantic search here, and how would you get training data for fine-tuning it?
How would you evaluate the search system both offline and online?
How would you handle personalization in search results given that different users in the same project have different roles and activity patterns?

“This question sprawled in every direction.”

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Atlassian·Machine Learning Engineer·Technical Phone Screen

Jul 2026

Atlassian ML engineer interview, got a nested list problem that looked straightforward but had a twist on the weighting scheme. Took me a bit to realize the depth calculation was inverted compared to the standard version.

Given a nested list of integers, return the sum of all integers weighted by their depth, where deeper integers have LOWER weight (weight = max depth minus current depth). How would you approach this?

“The classic version weights deeper integers more heavily, so I started going down that path before re-reading the prompt.”

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Atlassian·Software Engineer·Technical Phone Screen

Jul 2026

Atlassian software engineer interview with a system design coding problem focused on building an agent-rating service. The core challenge was less about getting something working and more about justifying your data structure choices under follow-up pressure.

Design and implement an agent-rating service with two operations: one to record a score (1-5) for a named agent and keep a running average, and another to return all agents ranked by average score descending. How do you keep this efficient?

“I jumped straight to the brute force because I wanted something on the board fast.”

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Atlassian·Software Engineer·Onsite - System Design / Architecture

Jul 2026

System design round at Atlassian for a software engineer role, focused entirely on building a trending/top-N posts feature for Confluence. Pretty deep dive, they wanted the full pipeline from event ingestion all the way through to serving.

Design a system that surfaces the top-N posts on Confluence based on engagement signals like views, likes, and comments within configurable time windows.

“This is a meaty one.”

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Atlassian·Software Engineer·Technical Phone Screen

Jul 2026

Atlassian SWE interview with a design-heavy coding problem that looked straightforward but had a lot of follow-up potential baked in. The discussion went longer than I expected once we got into trade-offs.

Design and implement a small system where records of (agent_id, rating) arrive over time. The system should compute each agent's average rating and return all agents sorted by average rating descending, with agent_id ascending as a tie-breaker.

“My first instinct was to store raw records and recompute averages on every query, which the interviewer let me talk through before nudging me to think about scale.”

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Atlassian·Machine Learning Engineer·Onsite - System Design / Architecture

Jul 2026

System design round at Atlassian for an MLE role. The whole thing was one big design question about building a RAG system on top of Jira and Confluence, which sounds straightforward until you get into the permissions and freshness requirements.

Design a RAG system that lets employees ask questions across Jira and Confluence, including cross-product queries like 'what's the status of project X and where's the design doc for it?'
How would you handle document-level permissions so users only retrieve content they're authorized to see?
Jira updates very frequently while Confluence changes less often. How does your ingestion pipeline handle that difference?
How would you make sure the generated answers cite the source Jira issues or Confluence pages correctly?
How would you evaluate this system both offline before shipping and online once it's live?

“This was the whole interview basically.”

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Atlassian·Software Engineer·Onsite - System Design / Architecture

Jul 2026

System design round at Atlassian focused entirely on building a tagging system with a heavy emphasis on REST API design. The problem felt deceptively scoped but the edge cases and concurrency bits made it genuinely tricky.

Design a tagging system (like tagging pages or issues) with a focus on REST API design. Cover CRUD for tags, attaching and detaching tags from entities, listing tags per entity, and searching entities by tag with AND/OR semantics.
How would you handle concurrency and idempotency for tag attach and detach operations?
Walk through the edge cases: what happens when you delete a tag that's still attached to entities, how do you handle rename collisions within a workspace, and how do you approach bulk attach/detach?
How would you design pagination for the tag list and entity search endpoints?

“This is the kind of question where you think you've got it in the first five minutes and then you don't.”

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