Backend Engineer II - Task Queue Coding Exercise (Candidate Instructions)

task-queue-candidate.md

Task Queue Processor — Coding Exercise

Overview

Build a simple in-memory task queue in Python. Get as far as you can in 20 min.

Requirements

Implement a class with the following methods:

add_task(task_id, priority, payload)

• Adds a task to the queue
• Higher priority numbers = higher priority (e.g., priority 10 runs before priority 1)
• payload can be any data associated with the task

get_next_task()

• Returns the highest priority task and removes it from the queue
• Should return task information (id, priority, payload)

get_status(task_id)

• Returns the current status of a task
• Possible statuses: queued, processing, completed

complete_task(task_id)

• Marks a task as completed

Example Usage

queue = TaskQueue()

queue.add_task("task-1", priority=5, payload={"action": "send_email"})
queue.add_task("task-2", priority=10, payload={"action": "process_payment"})
queue.add_task("task-3", priority=1, payload={"action": "log_event"})

print(queue.get_status("task-1"))  # "queued"

task = queue.get_next_task()  # Returns task-2 (highest priority)
print(queue.get_status("task-2"))  # "processing"

queue.complete_task("task-2")
print(queue.get_status("task-2"))  # "completed"

Notes

• Focus on getting a working solution first
• Think aloud as you work — we want to understand your thought process
• Feel free to ask clarifying questions
• You may use AI coding assistants if that's part of your normal workflow