Atlassian Backend Engineer First three rounds.
Summary
I went through the first three rounds for a Backend Engineer position at Atlassian, covering Karat (System Design), Data Structures, and Code Design rounds, with detailed questions provided for each.
Full Experience
Karat Round
Scaling a Web Service (Recipe + Products)
The web service allows users to browse recipes and purchase ingredients. It recently became popular and is facing performance bottlenecks.
→ What could be the potential issues and how would you improve the system?
Compute-Intensive Animation Generation
A service animates hand-drawn characters uploaded by kids. These jobs are compute-heavy and handled by a server farm.
→ How would you reduce infrastructure/server cost while maintaining user experience?
Unreliable Third-Party API
Your service depends on a third-party API (e.g., sports stats). The API has become unreliable and impacts UX.
→ What approaches would you take to mitigate the impact and improve reliability?
IoT Device Migration to Microcontroller
You’re migrating a smart appliance from an embedded computer (with Ethernet) to a resource-constrained microcontroller.
→ What factors should you consider in this migration, both from system and network perspectives?
Cost Estimation for Short Video Platform
Users upload short (≤1 min) videos with a TTL between 5–24 hours.
→ What factors should be considered to estimate the infrastructure cost for this platform over the next year if it becomes popular?
Data Structures Round
Max Price Tracker
Stream of (timestamp, price) data points. Timestamps can be duplicate and out of order.
→ Implement a system to return the maximum price at any point. Updates should override old prices.
Code Design Round
Product Rating System
Build a system with two APIs:
rateProduct(productId, rating)
getAllRatings() – returns all product average ratings sorted by highest average (then productId lexicographically)
→ Design it to handle real-time ratings and querying efficiently.
Interview Questions (7)
Scale a Recipe/Product Web Service
The web service allows users to browse recipes and purchase ingredients. It recently became popular and is facing performance bottlenecks. → What could be the potential issues and how would you improve the system?
Reduce Cost for Compute-Intensive Animation Service
A service animates hand-drawn characters uploaded by kids. These jobs are compute-heavy and handled by a server farm. → How would you reduce infrastructure/server cost while maintaining user experience?
Mitigate Impact of Unreliable Third-Party API
Your service depends on a third-party API (e.g., sports stats). The API has become unreliable and impacts UX. → What approaches would you take to mitigate the impact and improve reliability?
IoT Device Migration to Microcontroller Considerations
You’re migrating a smart appliance from an embedded computer (with Ethernet) to a resource-constrained microcontroller. → What factors should you consider in this migration, both from system and network perspectives?
Infrastructure Cost Estimation for Short Video Platform
Users upload short (≤1 min) videos with a TTL between 5–24 hours. → What factors should be considered to estimate the infrastructure cost for this platform over the next year if it becomes popular?
Max Price Tracker from Out-of-Order Stream
Stream of (timestamp, price) data points. Timestamps can be duplicate and out of order. → Implement a system to return the maximum price at any point. Updates should override old prices.
Design Product Rating System
Build a system with two APIs:
rateProduct(productId, rating)
getAllRatings() – returns all product average ratings sorted by highest average (then productId lexicographically)
→ Design it to handle real-time ratings and querying efficiently.