Atlassian Software Engineer Onsite Coding Questions

I had my Karrat interview a few weeks ago. The interview was a Snake game; these kinds of questions aren't difficult, but there are many corner cases to consider and handle well. VO: Coding 1: Likou57

**Infection Sequences Count** **Problem Description** There are $n$ houses aligned in a straight line, numbered 1 to $n$. An integer array `infectedHouses` represents the houses initially infected wit

**Candidate Profile** * **Experience:** 13 Years (B.Tech, CSE) * **Target Role:** Principal Engineer (Remote) * **Company:** Atlassian * **Date:** September 2025 * **Outcome:** Offer down-leveled to S

LeetCode #432: All O`one Data Structure. Difficulty: Hard. Topics: Hash Table, Linked List, Design, Doubly-Linked List. Asked at Atlassian in the last 6 months.

## Problem A customer support system stores satisfaction surveys as `(ticket_id, customer_id, agent_id, score, timestamp)` where score is 1-5. Implement a `SatisfactionAnalyzer`: ```python class SatisfactionAnalyzer: def add_response(self, ticket_id: str, customer_id: str, agent_id: str, score: int, ts: int) -> None: ... def agent_avg(self, agent_id: str) -> float: ... # overall average score def agent_trend(self, agent_id: str, window: int) -> float: ... # avg over last `window` responses def top_agents(self, n: int) -> list[tuple[str, float]]: ... # top n by overall avg, desc def customer_history(self, customer_id: str) -> list[tuple[str,int]]: ... # returns (ticket_id, score) sorted by timestamp asc ``` **Example:** ``` sa = SatisfactionAnalyzer() sa.add_response("T1","C1","A1",5,1000) sa.add_response("T2","C2","A1",3,2000) sa.add_response("T3","C1","A2",4,3000) sa.agent_avg("A1") -> 4.0 sa.agent_trend("A1", 1) -> 3.0 sa.top_agents(1) -> [("A2", 4.0)] ``` ## Follow-ups - How would you implement `agent_trend` in O(1) per query using a sliding window? - Extend to flag agents whose 7-day trend is declining by more than 1 point vs their overall average. - What database schema and indexes would you use to support these queries at scale?

## Problem A tennis club has `C` courts and receives booking requests as `(player_id, start_time, end_time)`. Process requests in order of arrival. Assign a request to any available court. If all courts are busy, add the request to a wait queue; it will be assigned when the earliest-ending match finishes. Return the final assignment list: `(player_id, court_id, actual_start_time)`. ```python def schedule_courts( num_courts: int, requests: list[tuple[str, int, int]] ) -> list[tuple[str, int, int]]: ... ``` **Example:** ``` num_courts = 2 requests = [("A",0,60),("B",0,90),("C",10,70),("D",20,50)] Output: [ ("A", 1, 0), ("B", 2, 0), ("C", 1, 60), # court 1 free at 60, C plays 60->120 ("D", 1, 120) # or court 2 free at 90 -> D at 90 ] ``` ## Follow-ups - What priority queue operations are needed, and what is the overall time complexity? - How do you handle a request where `end_time - start_time` varies (duration-based rather than fixed end)? - Extend to support VIP players who jump the wait queue.

(Omitted: only an external link/title is provided; the full statement, I/O format, and constraints are missing, so it cannot be reconstructed reliably.)

Given an integer N and an infinite stream of integers, implement a data structure/class that supports ingesting the next integer and returning the average of the most recent N integers (if fewer than

## Problem: Smallest Department Covering Two Employees (LCA Variant) A company's org structure is represented as a tree: - **Internal nodes** are `departments`. - **Leaf nodes** are `employees`. - A

## Problem: Implement a Time-Bucket-Based Rate Limiter Implement a rate limiter with the function: ```java boolean shouldPass(int timeBucket) ``` - `timeBucket` is the bucket id of the incoming req

Change the URL fetching from sequential to **parallel** execution. **Requirements** - Input: a list of URLs. - Behavior: send HTTP GET requests in parallel. - Output: a list of results. - If order

Extend the sequential URL fetcher by **deduplicating URLs** before sending requests. **Requirements** - Input: a list of URLs that may contain duplicates. - Behavior: fetch only unique URLs (optional

Given a binary tree and two nodes, find their lowest common ancestor. This is a variant of the Lowest Common Ancestor (LCA) problem. Please write a function to implement this functionality. ### Sampl

Design a data structure to calculate the moving average of a sliding window. Implement a class with the following operation: - `next(val)`: Add the element `val` and return the average of all elemen

Given a set of intervals, find all overlapping intervals. You need to output the start and end points of these intervals. ### Sample Input ``` [(1,4),(3,5),(6,8),(7,9)] ``` ### Sample Output ``` [(3

Given two strings `s` and `t`, determine if `s` is a subsequence of `t`. You may assume that there is only lowercase English letters in both strings `s` and `t`. The length of `t` is generally larger

Implement a function that given a list of tennis court bookings with start and finish times, returns a plan assigning each booking to a specific court, ensuring each court is used by only one booking

Design a service that performs CICD releases daily, and sends a notification to the author of a release success and deployment version. For example, Jason and Mike would be notified of their deploymen

Imagine you are part of the analytics team that tracks changing user trends. You’re tasked with calculating a moving average from a data stream with a window size of X. Now our engineers are intereste

Implement a function that given a list of tennis court bookings with start and finish times, returns a plan assigning each booking to a specific court, ensuring each court is used by only one booking