Overview
What this challenge is about.
Apply SOLID Principles to a Notifications Subsystem. Intermediate challenge in code. Writing production code that solves real engineering problems, earn a bl...
The Brief
What you'll do, and what you'll demonstrate.
Refactor a 5-channel Notifier applying SOLID principles and prove the design by adding a sixth channel with minimal file-touch.
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
- Apply each of the 5 SOLID principles to a real subsystem
- Design a plugin-style channel registry with dependency injection
- Prove a refactor's value by showing the cost of adding a new feature on top
- Sequence the refactor behind a feature flag with parity tests
Program Fit
Where this fits in your program.
Sharpens the same skills your degree expects you to demonstrate.
Software Design and Design Patterns
Master · Software Engineering
Strong alignment
This challenge maps to Software Design and Design Patterns at the Master level. It sharpens the same practical skills your coursework expects — but in a real industry context with actual constraints and deliverables.
Skills
Skills you'll demonstrate.
Each one shows up on your verified credential.
- Solid Principles
Apply solid principles to solve real industry problems and demonstrate production-level capability.
- Design Patterns
Apply design patterns to solve real industry problems and demonstrate production-level capability.
- Refactoring
Apply refactoring to solve real industry problems and demonstrate production-level capability.
- Dependency Injection
Apply dependency injection to solve real industry problems and demonstrate production-level capability.
- Feature Flags
Apply feature flags to solve real industry problems and demonstrate production-level capability.
- Characterization Testing
Apply characterization testing 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: