Overview
What this challenge is about.
Build a Metered-Billing System for a Usage-Based SaaS. Advanced challenge in code. Writing production code that solves real engineering problems, earn a bloc...
The Brief
What you'll do, and what you'll demonstrate.
Build a metered-billing pipeline that ingests usage events, aggregates without double-counting, and invoices accurately at month-end with full reconciliation.
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
- Design idempotent event ingestion under retries and out-of-order delivery
- Build a windowed aggregator that survives worker restart without double-counting
- Integrate with a webhook-driven subscription billing API safely
- Produce reconciliation reports a CFO will sign off on
Program Fit
Where this fits in your program.
Sharpens the same skills your degree expects you to demonstrate.
Aligned coursework coming soon.
Skills
Skills you'll demonstrate.
Each one shows up on your verified credential.
- Metered Billing
Apply metered billing to solve real industry problems and demonstrate production-level capability.
- Idempotency
Apply idempotency to solve real industry problems and demonstrate production-level capability.
- Event Aggregation
Apply event aggregation to solve real industry problems and demonstrate production-level capability.
- Typescript
Write type-safe code that scales across large codebases and teams.
- Webhooks
Apply webhooks to solve real industry problems and demonstrate production-level capability.
- Reconciliation
Apply reconciliation to solve real industry problems and demonstrate production-level capability.
Careers
Career paths this challenge builds toward
Completing this challenge demonstrates skills that transfer directly to these roles: