Computer Science
Testing & QA Challenges
Testing & QA challenges put you behind the safety net that lets software ship with confidence. You'll develop skills in Software Testing, Unit Testing, and Automated Testing, build End-to-end testing flows, and read Coverage Reports to find the gaps that matter before users do.
From there you'll handle the harder edges — Test architecture, Test pyramid discipline, Contract testing, and Load Testing — alongside Static Analysis, AI-assisted test generation, and regulated practices like ISO 17025 calibration and CAPA workflows. Each challenge you solve earns a verified credential you can share with recruiters.
Recommended Challenges
- CodeIntermediateNew
Build a Hybrid Recommendation System for an Indie Streaming Catalog
Use the provided 6-month anonymized event log (around 320M play events, 1.4M unique users in the held-out cohort), audio embeddings (256-d), and track metadata. Implement (1) an…
- Recommendation Systems
- Collaborative Filtering
- Content Based Recommendation
Open coursework - AnalysisIntermediateNew
Mine Basket History to Justify Grocery Shelf-Adjacency Changes
Work only from the materials provided. Use the basket transactions extract to mine frequent itemsets with FP-growth, tuning the minimum support level separately for the food, ho…
- Frequent Itemset Mining
- Fp Growth
- Spark
Open coursework - CodeBeginnerNew
Refactor a Tangled Java Pricing Engine With Design Patterns
Start from a provided Java 21 codebase with the legacy PricingEngine class, 38 example fixtures (input cart, expected price), and one failing test demonstrating a bug from last …
- Java
- Design Patterns
- Refactoring
Open coursework - CodeBeginnerNew
Build a Secure-Coding Linter Ruleset for a Backend Team
Using the findings log, study the twelve documented security-review findings and confirm the three repeat patterns. Then build a custom linter ruleset — choose Semgrep or custom…
- Secure Coding
- Static Analysis
- Semgrep
Open coursework Practice your coursework on real scenarios.
Every challenge is shaped from real-world context — not generic exercises. The work mirrors what your degree prepares you for.
Why Ewance
- AnalysisIntermediateNew
MCMC for Conversion-Funnel A/B Testing at a Marketplace
You receive 6 weeks of per-visitor funnel data (visit, sign-up, trial start, trial-to-paid conversion) split by variant and by acquisition channel (organic, paid social, paid se…
- Mcmc
- Bayesian Hierarchical Models
- Ab Testing
Open coursework - CodeBeginnerNew
Case File: Smart-Pointer Refactor of a Game-Engine Module
Work only from the four supplied items: the representative entity-component-system module slice, the before-refactor heaptrack leak readout, the de-identified incident log, and …
- Cpp Programming
- Manual Memory Management
- Pointers
Open coursework - AnalysisIntermediateNew
Capacity Planning Model for a Black-Friday Traffic Surge
Pull 18 months of per-service request rate + utilization from Prometheus. Forecast BFCM traffic per service using a baseline + multiplicative seasonal model (Prophet or statsmod…
- Capacity Planning
- Forecasting
- Autoscaling
Site Reliability Engineering - CodeSeniorNew
Detect Use-After-Free with Pointer Analysis in a C++ Codebase
Build the codebase with compilation database (compile_commands.json). Write a custom Clang static-analyzer checker (or extend an existing one) that flags resource-handle uses af…
- Pointer Analysis
- Static Analysis
- Use After Free
Open coursework - Browse challenges
Explore role
Product Manager
Ship product that solves real user problems. Combine user research, prototyping, and stakeholder alignment to turn ambiguous briefs into measurable wins — the role at the centre of modern software teams.
- CodeBeginnerNew
Build a Source-to-Source Migration Tool for a Legacy API
Use Python's libcst (concrete syntax tree library) to parse customer code while preserving formatting. For each of the 14 transformations, write a CST visitor that matches the v…
- Abstract Syntax Trees
- Source To Source Transformation
- Python
Open coursework - DesignIntermediateNew
Rate and Reduce Technical Debt in a Telecom OSS Codebase
Design a SQALE-based technical-debt rating and improvement proposal for Lumera Telekom's OSS. Using only the static-analysis findings export, the module inventory and rating gri…
- Sqale Method
- Technical Debt
- Code Quality
Open coursework - DesignBeginnerNew
A/B-Test a Recommender Improvement Without Breaking Trust
You receive offline-evaluation results for both the production and candidate models plus aggregate metrics from the last 12 weeks (recipe views, save rate, weekly active users, …
- Experiment Design
- Ab Testing
- Metric Design
Machine Learning in Practice - CodeIntermediateNew
Find the Dead Code Hiding in a Python Monorepo
Build a dataflow- and call-graph-based dead-code detector in Python (using libcst, or the standard ast module together with jedi) and prove it on the materials provided. Run it …
- Dataflow Analysis
- Ast
- Call Graph
Open coursework Build a verifiable portfolio.
Submissions become evidence. Reviewers with shipping experience score against a rubric; the result becomes a credential anyone can verify.
Why Ewance
- DesignIntermediateNew
Design an Adaptive Home Screen for a Streaming Recommender
Using the recommender output specification and the session-signals fixture, design three adaptive layout variants that are each triggered by a viewing-intent signal derived from…
- Adaptive Interfaces
- Interaction Design
- A B Testing
Open coursework - AnalysisIntermediateNew
Build a Technical Debt Register for a Legacy Banking Monolith
Run 8 structured 45-minute engineer interviews (template provided) capturing one debt item per pain point with reproducible evidence. Run SonarQube against the monolith for a qu…
- Technical Debt
- Debt Quadrant
- Code Quality
Technical Debt Management - CodeIntermediateNew
Debug a Race Condition in a Real-Time Collaboration Service
Build a deterministic load-test harness (k6 or Playwright) that reproduces the corruption within 3 attempts on a clean local stack. Capture traces with OpenTelemetry to localize…
- Debugging
- Concurrency
- Load Testing
Software Construction - CodeBeginnerNew
Build and Ship a Bug-Tracker MVP with Full CI/CD
Week 1: write a 1-page SRS + Figma wireframes for 5 screens (login, bug list, bug detail, file bug, dashboard). Week 2-3: implement with Next.js + Supabase + Tailwind, with unit…
- Full Stack Development
- Requirements Engineering
- Ci Cd
Software Engineering Foundations - CodeIntermediateNew
Build a CodeQL Query Pack to Catch Logging of Personal Data
Using the provided personal-data source and logging-sink specification, write CodeQL data-flow queries for Java and Python that detect personal data travelling from a source (re…
- Static Analysis
- Codeql
- Data Flow Analysis
Open coursework - CodeIntermediateNew
Build a Canary Rollout for a Production Recommender
Pick a serving stack (Triton, Seldon Core, KServe, or BentoML). Implement two-model traffic splitting with a configurable percentage (start at 5%). Wire up online metric collect…
- Canary Deployment
- Kubernetes
- Ab Testing
ML Engineering and Production ML - DesignSeniorNew
Design a Semantic Configuration Validator Using Abstract Interpretation
Using the configuration schema reference, the three incident post-mortems, and the 200-configuration validation set provided, design an abstract domain that captures relations b…
- Abstract Interpretation
- Static Analysis
- Rust Programming
Open coursework - DesignSeniorNew
Design a Symbolic-Execution Test-Generation Pipeline for a Date-Time Library
Design a generation pipeline that turns the public parsing and arithmetic surface of the supplied library module into branch-covering test inputs using a symbolic-execution engi…
- Symbolic Execution
- Klee
- Test Generation
Open coursework - DesignBeginnerNew
Design a Lexer and Parser for a Customer Query Language
Using the grammar sketch, the query corpus sample, the Abstract Syntax Tree schema, and the edge-case suite provided to you, write a design proposal for a new lexer and parser t…
- Lexing
- Recursive Descent Parsing
- Abstract Syntax Trees
Open coursework - StrategyBeginnerNew
Code Review Bootcamp for an Early-Stage Mobile Team
Read the team's last 100 merged PRs (export provided) and tag the 10 worst review threads (rubber-stamp, bikeshed, missing context). Draft a 4-page code-review guideline coverin…
- Code Review
- Team Coaching
- Process Design
Software Construction - AnalysisBeginnerNew
Code-Smell Triage Workshop for a Hiring-Platform Backend
Run static analysis (SonarQube + a custom ruleset for domain-specific smells) on the four most-touched services. Score each smell on the 22-item Fowler catalog by occurrence cou…
- Code Smells
- Static Analysis
- Refactoring Prioritization
Open coursework - AnalysisIntermediateNew
Measure HTTP/3 vs HTTP/2 Video Delivery Over Cellular
Using the architecture brief, the four-week quality-of-experience dataset, the cellular-and-video-profiles specification, and the starter synthetic-client harness module (all pr…
- Quic Http3
- Network Measurement
- Transport Protocols
Open coursework
How it works
From brief to credential, in six steps.
Step 01
Browse challenges aligned to your studies.
Step 02
Accept the one that fits your goals.
Step 03
Work through it with AI Copilot guidance.
Step 04
Submit for structured evaluation.
Step 05
Earn a verified credential.
Step 06
Add it to LinkedIn with one click.
Related skill families
Browse all skillsIndustry teams behind a decade of practitioner briefs
Hiring from this pool?
Sponsor a challenge and meet candidates through actual work.
Industry teams can shape briefs around the skills they hire for, then evaluate students on rubric-scored deliverables — not resumes.