Computer Science
Programming Fundamentals Challenges
Programming Fundamentals challenges put you inside the work of writing code that is correct, readable and fast. You'll build core skills in functions & data structures, object-oriented design and design patterns, work in Python or JavaScript, and learn to do code reading and refactoring the way teams expect.
From there you'll tackle the harder edges — algorithm analysis, complexity analysis, graph algorithms and generics & type systems — pushing into performance engineering, low-latency programming patterns and systems-language proficiency (Go, Rust, C++). Each challenge you solve earns a verified credential you can share with recruiters.
- CodeBeginnerNew
Hybrid Search RAG for a HR-Policy Assistant
You receive 1,800 pages of policy documents (Markdown) and 150 labeled question-answer pairs with the gold source policy IDs. Build a hybrid retrieval pipeline: BM25 + dense emb…
- Hybrid Search
- Bm25
- Dense Retrieval
Retrieval-Augmented Generation - CodeIntermediateNew
Build an Evaluation Harness for an Internal LLM Assistant
You will design and implement an evaluation harness in Python that runs four test suites: (1) helpfulness (LLM-as-judge with rubric), (2) factual grounding (compare cited source…
- LLM Evaluation
- LLM As Judge
- Prompt Injection Testing
Large Language Models - CodeBeginnerNew
Build a CPU-Only Teaching Rasterizer in C++
Using the provided test-scene model file and the reference render image, implement a software rasterizer in C++ that runs only on the central processor. Build the supporting mat…
- Rasterization
- Geometric Transformations
- 3d Rendering
Open coursework - CodeIntermediateNew
Build a Feature Store Backbone for a Healthtech ML Team
You receive synthetic wearable telemetry (heart rate, accelerometer, sleep stages) for around 5,000 patients across 90 days, plus the existing scattered feature scripts from the…
- Feature Engineering
- Data Modeling
- Python
Data Engineering and Big Data Systems Develop in-demand professional skills.
Each challenge names the skills it strengthens. Over time, your profile fills with the competences a hiring manager would actually look for.
Why Ewance
- AnalysisBeginnerNew
Map Creator Communities for a Short-Form Video Platform
You receive a 90-day sample of about 4 million creator-creator interactions (duets, mentions, audience overlap) and creator metadata (region, language, content tag). Build a cre…
- Network Analysis
- Community Detection
- Graph Visualization
Social Network Analysis and Web Science - CodeIntermediateNew
Prove a gRPC Migration for a Kubernetes Control-Plane API
Examine three things: the captured control-plane traffic record (`traffic-7d`), the current REST API specification (`openapi-spec`), and the representative Go service module (`g…
- Grpc
- Protobuf
- API Design
Open coursework - CodeBeginnerNew
Design a Domain Model for a Library Loan System (Java)
Implement, in Java 21, an Item type hierarchy (Book, AudioBook, Periodical, EquipmentLoan — each with sub-type-specific rules), Member with eligibility logic, Loan as an aggrega…
- Java
- Oo Design
- Domain Modeling
Object-Oriented Programming and Design 
CodeBeginnerNewBuild a Pricing-Aware Scheduling Agent for Smart Thermostats
Using only the materials provided, build an intelligent agent with four working parts: perception (read the sensor history), learning (cluster each household's comfort intervals…
- Intelligent Agents
- Basic Learning
- Python Programming
Open coursework- Browse challenges
Explore role
Strategy Analyst
Frame the business question, model the options, build the recommendation. From market sizing to competitive analysis, this role is where strategy consulting meets in-house decision-making.
- CodeIntermediateNew
Strangler-Fig Migration of a Monolithic Order Service
Stand up an HTTP facade in front of the monolith (Nginx or a small Go proxy) that routes by URL pattern. Slice 1: extract the order-status read endpoint, dual-write nothing, rou…
- Strangler Fig Pattern
- Refactoring
- Legacy Modernization
Refactoring and Code Smell Detection - CodeIntermediateNew
Forecasting Model for Online-Game Daily Active Users
Build forecasts at 14-day horizon per region using: (1) classical baseline — SARIMA or Prophet; (2) ML approach — gradient-boosted regressor on engineered features (day-of-week,…
- Supervised Learning
- Time Series Forecasting
- Python Programming
Machine Learning (CS Elective) - CodeIntermediateNew
Build a Hybrid Recommender for a Niche Consumer-AI Music App
You receive listening events (around 240 million plays) plus a content embedding per track (audio + curator tags). Build a collaborative filtering model (ALS or implicit-feedbac…
- Recommender Systems
- Collaborative Filtering
- Content Based Filtering
Data Mining and Knowledge Discovery - CodeIntermediateNew
Plan Inventory Replenishment as an MDP for an E-Commerce AI Startup
You receive 18 months of daily demand for 50 representative SKUs at one warehouse plus lead-time and unit-cost data. For one SKU at a time, formulate an MDP with state = (on-han…
- Mdp Modeling
- Value Iteration
- Dynamic Programming
Decision Making Under Uncertainty Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- AnalysisIntermediateNew
Audit BLEU vs. COMET on a Multilingual Customer-Support Corpus
You receive 600 source-translation-reference triples covering 6 languages (EN as source; ES/FR/DE/JA/PT-BR/HI as targets), each scored on adequacy and fluency (1-6) by 3 profess…
- Mt Evaluation
- Neural Mt
- Statistical Analysis
Machine Translation - CodeBeginnerNew
Optimize Wind-Turbine Layout with a Genetic Algorithm
You receive a wind-speed-and-direction time series for the lease area, the polygon boundary, a minimum inter-turbine spacing constraint, and a Jensen wake model. Implement a rea…
- Genetic Algorithms
- Metaheuristics
- Constraint Handling
Evolutionary Computation and Metaheuristic Search - CodeIntermediateNew
Stream-Process a 64-Microphone Array to Locate Bearing Faults in Real Time
Using the provided fixture generator and array-geometry spec, implement an overlap-add streaming pipeline that consumes 64 channels in 1,024-sample frames with 50 percent overla…
- Fft
- Signal Processing
- Beamforming
Open coursework - CodeIntermediateNew
Build a WCAG 2.2 AA Accessible Chart Component Library
Build a React and TypeScript component library that exports four chart components (bar, line, scatter, heatmap), each rendering the figures in the provided sample analytics data…
- Accessibility
- Wcag 2
- React
Open coursework - AnalysisIntermediateNew
Diagnose a Memory-Hierarchy Bottleneck in a Trading-System Hot Path
Receive the normalizer source (around 4,000 lines of C++17), a replay harness that feeds 30 minutes of recorded market data, and host-machine specifications (Intel Xeon Gold 634…
- Memory Hierarchy
- Performance Profiling
- Perf
Computer Systems and Organization - AnalysisBeginnerNew
Optimizing Last-Mile Delivery for a San Francisco Grocery Startup
Your task is to formulate a minimum-cost flow problem for daily delivery routes. Use the provided order data (locations, time windows, volumes) and vehicle specs (capacity, spee…
- Linear Programming
- Network Flow
- Python
Operations Research and Optimization - CodeIntermediateNew
Build an Anomaly-Detection Pipeline for Pharma Cold-Chain Logistics
You receive 18 months of shipment telemetry (around 60,000 shipments, around 12 million sensor readings) plus a hand-labeled set of 1,200 incidents (mix of true excursions, sens…
- Anomaly Detection
- Feature Engineering
- Time Series
Data Mining and Knowledge Discovery - CodeIntermediateNew
Apply the Mikado Method to Untangle a Tax-Engine Class
Starting from the live codebase (Java 17, 73 percent line coverage), write a failing test that asserts the desired end state ('TaxCalculator is decomposed into per-country strat…
- Mikado Method
- Refactoring
- Strategy Pattern
Refactoring and Code Smell Detection - AnalysisIntermediateNew
Compare Kernel SVMs and Gradient Boosting on Imbalanced Tabular Data
You receive a 220,000-row anonymized loan-default dataset with mixed numeric and categorical features and a ~6% positive class. Train and evaluate (1) an RBF-kernel SVM with pro…
- Kernel Methods
- Gradient Boosting
- Model Selection
Machine Learning - CodeBeginnerNew
Design and Implement a C++ Telemetry Aggregator With Inheritance
Implement a TelemetrySource abstract base class with virtual sample() and timestamp() methods, 6 concrete subclasses (one per sensor family), and a TelemetryBus that polymorphic…
- Cpp
- Inheritance
- Polymorphism
Object-Oriented Programming and Design - DesignBeginnerNew
Greedy Delivery-Slot Assignment for a Munich Grocery Startup
Using the provided order history sample, rider roster, and manual dispatch baseline, design and implement a greedy slot-assignment algorithm in Python. The algorithm must (1) so…
- Greedy Algorithms
- Algorithm Analysis
- Python
Open coursework - CodeFoundationalNew
Swap a List Scan for a Min-Heap in the Dispatcher
Working only from the materials provided, your job is to make the courier-selection logic faster and to show, with evidence, that it actually got faster. First, read the de-iden…
- Heap Data Structure
- Complexity Analysis
- Python
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.