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.
- CodeIntermediateNew
Kill Surviving Mutants in a Travel Pricing Service
Work entirely from the provided pricing module (pricing-module) and its existing test suite (existing-tests), using the scenario facts in the briefing document (challenge-brief)…
- Mutation Testing
- Java
- Junit
Open coursework - CodeBeginnerNew
Build a Credit-Card Fraud Detector for a Singapore Neobank
You receive 9 months of anonymized authorization data (around 8 million transactions, around 0.4 percent fraud) plus current rule outcomes. Split temporally and train at least t…
- Classification Modeling
- Class Imbalance
- Model Calibration
Open coursework - AnalysisBeginnerNew
Community Detection on a Pharma Clinical-Trial Investigator Graph
You receive a pre-fetched dump of around 15,000 trials from a public registry covering oncology over the last 10 years and a mapping of trials to investigator names + institutio…
- Community Detection
- Louvain
- Leiden
Open coursework - CodeIntermediateNew
Build a Forgetting-Curve-Aware Spaced-Repetition Engine
You receive 6 months of practice logs from 8,000 learners (item, timestamp, response correctness, response latency). Fit a learner-personalized forgetting model (logistic per-it…
- Spaced Repetition
- Personalization
- Behavioral Data
Open coursework 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
Cluster a Telco's Subscriber Base for a Pricing Refresh
You receive 12 months of anonymized subscriber-level data: monthly minutes, SMS, mobile data, top-up frequency, top-up amount, churn flag, and tenure. Clean and feature-engineer…
- Clustering
- Feature Engineering
- Exploratory Data Analysis
Data Mining and Knowledge Discovery - StrategyBeginnerNew
Introduce XP Practices to a Legacy E-Commerce Codebase
Run a 6-week intervention with the 7-person checkout team. Week 1: baseline (current test coverage, defect-escape rate, story cycle time). Weeks 2-5: introduce TDD on all new co…
- Extreme Programming
- Test Driven Development
- Pair Programming
Agile Methods and Practices - 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 - AnalysisIntermediateNew
Run a Pre-Deployment Fairness + Drift Audit on a Hiring Model
You receive a trained classifier (joblib), the training data sample, and a held-out 'next-month' evaluation set. Compute group fairness metrics (false-positive-rate gap, true-po…
- Fairness Metrics
- Drift Detection
- Bias Mitigation
Machine Learning in Practice - Browse challenges
Explore role
Pricing Strategist
Set the price that captures value without leaving sales on the table. Demand modelling, willingness-to-pay research, and the disciplined experimentation that turns pricing into a competitive advantage.
- 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 - 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 - AnalysisIntermediateNew
Design an Electronic Health Record Data-Quality Audit
Stand up a Python (pandas + DuckDB) audit notebook ingesting the 14M-record extract. Define and run quality checks across four dimensions: completeness (required-field missingne…
- Health Informatics
- Data Quality
- Snomed Ct
Computational Biology and Health Informatics - CodeIntermediateNew
Refactor a Big-Ball-of-Mud Java Servlet Application
Week 1: install JUnit 5 + Testcontainers harness, write characterization tests for the 2 target workflows (PolicyIssue + ClaimSubmit) reaching at least 80 percent branch coverag…
- Refactoring
- Characterization Testing
- Legacy Systems
Software Evolution and Maintenance Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- DesignIntermediateNew
Design a UV-Preserving Mesh Simplification Pipeline for 3D-Scan-to-Web
Using the textured high-resolution meshes in the scan corpus (scan-corpus), the engineering constraints in the engineering brief (engineering-brief), the integration contract in…
- Geometry Processing
- Mesh Simplification
- 3d Rendering
Open coursework - ResearchIntermediateNew
Audit Recommender Filter Bubbles for a Civic Forum
You receive 90 days of impression logs (about 30 million recommendation events) tagged with content viewpoint labels (left-leaning, center, right-leaning, non-political) from an…
- Recommender Evaluation
- Diversity Metrics
- Audit Methodology
Open coursework - CodeIntermediateNew
Build an End-to-End ML Pipeline for Loan-Default Prediction
You receive 24 months of historical application + outcome data (about 380,000 rows). Build a pipeline using a workflow orchestrator (Prefect, Kedro, or a simple Makefile chain) …
- Ml Pipelines
- Feature Engineering
- Pipeline Testing
Open coursework - AnalysisBeginnerNew
Model Diffusion of a Hashtag Across a Music-Discovery Platform
You receive 30 days of hashtag-usage data (about 2.4 million events) with account metadata and the follow graph between active hashtag users. Fit an information-diffusion model …
- Diffusion Models
- Network Analysis
- Causal Attribution
Social Network Analysis and Web Science - CodeIntermediateNew
AI-Driven Sales Lead Scoring for a B2B SaaS Scale-Up
You will receive a sample dataset of 200 leads with fields like company size, industry, email open rates, and website visits. Using AI tools, you must craft prompts to generate …
- Prompt Engineering
- Lead Scoring
- Data Analysis
Open coursework - ResearchBeginnerNew
Drug-Repurposing Candidate Screen with Embedding Similarity
You receive (1) a list of 15 known therapeutic candidates (SMILES + ChEMBL identifiers) for a single rare disease, (2) a database of about 4,500 marketed drugs (SMILES + ATC cod…
- Molecular Embeddings
- Similarity Search
- Transfer Learning
Machine Learning for Healthcare and Biomedicine - StrategyBeginnerNew
IDE-Assisted Refactoring Bootcamp for a Junior Backend Team
Design a 5-day curriculum centered on 10 katas chosen for refactoring-pattern coverage (e.g., Gilded Rose for replace-conditional-with-polymorphism, Tennis kata for extract-meth…
- Refactoring
- Katas
- Ide Tooling
Refactoring and Code Smell Detection - CodeBeginnerNew
Build Semantic Search for an Internal Engineering Wiki
You receive a Confluence XML export (~12k pages, ~80 MB of text) and a hand-labeled benchmark of 50 internal queries with ground-truth doc IDs. Chunk and embed the corpus with a…
- Embedding Models
- Vector Search
- Pgvector
Vector Databases and Embeddings - CodeBeginnerNew
Forecast Hourly Energy Demand for a Microgrid Operator
You receive 24 months of hourly demand, weather (temperature, irradiance), and calendar data for the community. Build a probabilistic forecaster (e.g., quantile regression with …
- Probabilistic Forecasting
- Quantile Regression
- Deep Forecasting
Open coursework - ResearchIntermediateNew
Design a Capability Evaluation for an Open-Weights Coding Model
Pick a recent open-weights coding model (e.g., a Qwen, DeepSeek, or Llama variant). Design an evaluation set of around 40 coding tasks across 4 buckets: standard benign coding, …
- Capability Evaluation
- Safety Evaluation
- LLM Evaluation
AI Safety and Alignment - CodeSeniorNew
Design an In-House Bare-Metal Bootloader for a Smartwatch Prototype
Working only from the provided materials, design and implement a bare-metal C bootloader for the Cortex-M4 target with no operating system, a custom linker script, and vector-ta…
- C Programming
- Manual Memory Management
- Pointers
Open coursework - CodeIntermediateNew
Prototype a Computer-Vision QA Tool for a Robotics Manufacturer
As a 4-person team, build: (1) a labeling pipeline on around 2,000 component images (Label Studio is fine); (2) a transfer-learned classifier or a small segmentation model that …
- Computer Vision
- Transfer Learning
- Model Deployment
AI Software Engineering Group Project
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.