SYSTEM DESIGN

Atlassian System Design Questions

11 distinct system design problems asked at Atlassian from September 2025 to September 2026, merged from 11 candidate reports. Each one links to a full solution.

Sources: PracHub, LeetCode discussions. Sorted by how often the problem was reported at Atlassian.

Design Monitoring and Reliability for 99.99% Availability

Design an internal metrics monitoring platform like Datadog or Prometheus. Agents on hosts and services emit metrics (counters, gauges, histograms with tags); the system ingests millions of data points per second, stores them as…

HLD1 report·last Sep 2026·also asked at 6 other companies

Design a distributed rate limiter service

Design a distributed rate limiter that protects APIs by limiting requests (or consumed units such as LLM billing tokens or storage quota) per user, API key, tenant, or IP. It must support configurable rules (e.g., 100…

HLD1 report·last Feb 2026·also asked at 12 other companies

Design a simple greeting-card web app

Design a simple web application (MVP) for creating and sending greeting cards: users choose a template, customize the message and images, and send the card to a recipient by email or link, who can view it. Discuss the minimal…

HLD1 report·last Feb 2026

Design a Data Stream Processor

Design a real-time data stream processor: ingest a high-throughput stream of events, validate and transform them, compute aggregations over time windows, and output results to downstream sinks. Requirements: ordering where…

HLD1 report·last Feb 2026

Design a scalable chatbot platform

Design a ChatGPT-style conversational AI product. Users send a message and receive a streamed response from a model; conversations persist and can be resumed on any device; the service must stay highly available despite limited,…

HLD1 report·last Jan 2026·also asked at 5 other companies

Diagnose why a scaled system became slow

A production service has become slow after scaling up (or a single-node web server is down). Walk through how you would diagnose the problem: which metrics, logs and traces you would check, how you would form and test hypotheses…

HLD1 report·last Jan 2026·also asked at 1 other company

Compute top-N posts in a workspace

Design a system that continuously computes the top K items from a very large event stream: for example the K most-viewed URLs, the K services with the most error logs in the last 5 minutes, the top 100 most active users in a…

HLD1 report·last Jan 2026·also asked at 7 other companies

Design an image crawler for unlimited URLs

Design a distributed web crawler that starts from seed URLs and crawls about 10 billion pages (or all images reachable from given root URLs), with periodic recrawls. It must avoid fetching the same URL twice, obey robots.txt and…

HLD1 report·last Jan 2026·also asked at 5 other companies

Design an access control system (RBAC + resource-based)

Design an authorization system that supports both role-based access control (users and groups have roles such as Admin, Editor or Viewer that grant permissions) and resource-level ACLs (individual resources grant or deny specific…

HLD1 report·last Jan 2026·also asked at 2 other companies

Design a tagging system and REST APIs

Design a tagging system (like tags on Confluence pages or Jira issues) with a strong focus on REST API design. Support creating, renaming and deleting tags; attaching and detaching one or more tags to entities; listing tags for…

HLD1 report·last Jan 2026

Store a hierarchy and return all children

Design a service that stores a hierarchical tree (or forest) of nodes and exposes APIs to add a node under a parent, move a subtree, delete a node, and return all descendants (all children at any depth) of a node efficiently.…

HLD1 report·last Jan 2026

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