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Swap a List Scan for a Min-Heap in the Dispatcher

FreeVerified credential2 weeksBeginner

Overview

What this challenge is about.

Swap a List Scan for a Min-Heap in the Dispatcher. Beginner-friendly challenge in code. Writing production code that solves real engineering problems, earn a...

CredentialBlockchain-anchored
ShareableLinkedIn-ready
LanguageEnglish
PaceSelf-paced

The Brief

What you'll do, and what you'll demonstrate.

Replace the dispatcher's linear scan over about 4,000 courier records with a binary min-heap keyed on eligibility score, and prove on a recorded operation sample that selection got faster without changing which courier is chosen.

This is not a coding exercise. It is the work a software engineer does between a Jira ticket and a merged PR. That distinction matters to every hiring manager who has seen candidates solve LeetCode problems and none who have shipped production code under real constraints.

When you finish, you will have something most graduates do not: a real-world deliverable, verified by Ewance, that you can show to a hiring manager and say "I did this. Here is the proof."

Earning criteria — what you'll demonstrate

  • Identify a hot linear scan in existing code from profiler evidence and reason about its time complexity
  • Implement a binary min-heap with an auxiliary index enabling O(log n) decrease-key on a specific element
  • Refactor a data structure inside a live service without changing its observable behavior
  • Design a before/after benchmark that isolates the change and reports both average and tail latency
  • Communicate an algorithmic improvement in plain language to a non-expert audience

Program Fit

Where this fits in your program.

Sharpens the same skills your degree expects you to demonstrate.

Aligned coursework coming soon.

Careers

Career paths this challenge builds toward

Completing this challenge demonstrates skills that transfer directly to these roles:

Backend Engineer

Replacing a hot data structure in a live service and proving the win mirrors everyday backend work: spot a bottleneck from profiling, refactor safely without changing behavior, and defend the result with numbers your teammates trust.

This challenge sharpens

  • heap-data-structure
  • code-refactoring
  • benchmarking

Site Reliability Engineer

Reading an incident record, confirming the cause from profiler data, and reducing tail latency on a critical path is core reliability work. This challenge builds the habit of measuring before and after rather than guessing at performance.

This challenge sharpens

  • benchmarking
  • complexity-analysis
  • python

Performance Engineer

Turning an O(n) scan into an O(log n) operation and quantifying the saving is the essence of performance engineering. You practice isolating a change, measuring average and p99 cost, and communicating the trade-off clearly.

This challenge sharpens

  • complexity-analysis
  • benchmarking
  • technical-writing

One more thing

You can put a credential on your CV by Friday.