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
Build a Plugin-Based Notification Framework With Observer + Factory
Implement, in Java 21: an EventBus that supports typed subscriptions, a NotificationChannel interface with concrete subtypes (Push, Email, InApp, SMS), an AbstractChannelFactory…
- Java
- Design Patterns
- Oo Design
Object-Oriented Programming and Design - CodeBeginnerNew
Characterization Tests for an Untested Pricing Engine
Drive the pricing engine with around 800 representative input vectors generated from anonymized production quotes (provided). For each vector, capture the current output as the …
- Characterization Tests
- Approval Testing
- Legacy Code
Refactoring and Code Smell Detection - CodeSeniorNew
Implement a Proof-of-Stake Consensus Mechanism in Rust
Read the Casper FFG paper (Buterin + Griffith, 2017) and design a simplified PoS implementation in Rust: 21 validators, 32-slot epochs, two-phase finality (justify, then finaliz…
- Consensus Algorithms
- Blockchain Protocols
- Rust
Blockchain and Decentralized Systems Engineering - AnalysisBeginnerNew
Build a Topic-Modeling Pipeline for Citizen Feedback
Take the 60,000 comments (anonymized). Build a BERTopic pipeline with multilingual sentence embeddings (Catalan + Spanish + occasional English). Tune number-of-topics via topic-…
- Topic Modeling
- Bertopic
- Multilingual NLP
Natural Language Processing 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
- CodeFoundationalNew
Rule-Based Intent Classifier for a Customer-Support Triage Bot
Build a rule-based classifier in Python that runs ordered rules (regex + keyword + simple heuristics) against ticket subject + body. Use a hierarchical rule structure (high-prec…
- Knowledge Representation
- Rule Based Systems
- Python Programming
Introduction to Artificial Intelligence (CS Elective) - CodeBeginnerNew
Train a Word-Alignment Model for Low-Resource Catalan-Aranese
You receive a 35,000-sentence Catalan-Aranese parallel corpus plus a 1,200-pair manually annotated word-alignment test set. Train (1) a classic statistical alignment baseline (e…
- Alignment
- Neural Mt
- Low Resource Mt
Machine Translation - AnalysisBeginnerNew
Detect Fraudulent Refund Requests for a Mid-Market Marketplace
You receive a labeled dataset with buyer history, seller history, shipping carrier, refund reason text, and outcome label (legit / fraud). Train and evaluate at least two classi…
- Classification
- Model Calibration
- Imbalanced Classification
Machine Learning (Undergraduate) - CodeIntermediateNew
Solve a Vehicle-Routing Problem with Tabu Search
You receive a week of anonymized daily VRPTW instances (around 800 orders per day, 120 vehicles, hard delivery windows). Implement tabu search with: a route-insertion constructi…
- Tabu Search
- Metaheuristics
- Vehicle Routing
Evolutionary Computation and Metaheuristic Search - Browse challenges
Explore role
Marketing Analyst
Plan and measure campaigns that grow the business. Funnel analytics, attribution, segmentation, and the rigorous measurement that lets marketing defend its budget at the leadership table.
- CodeSeniorNew
Grounded Language for a Robotics Pick-and-Place Demo
Use a tabletop simulator (PyBullet or Isaac Sim, both open) with 5 object types and 5 spatial relations (left of, right of, behind, in front of, on top of). Curate or generate a…
- Grounded Language Understanding
- Semantic Parsing
- Perception
Computational Semantics - 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
Compiler Construction - CodeSeniorNew
Build a Distributed Shared Memory Layer Over RDMA for Risk Engines
Build a Distributed Shared Memory library in C++ that exposes a small region interface — allocate a shared region, read from it, write to it, and free it — starting from the pro…
- Distributed Systems
- Rdma
- Consistency Models
Open coursework 
CodeBeginnerNewBuild a Search-Based Delivery Router for a Madrid Grocery Startup
Build a Python service that exposes a single /route endpoint. It accepts a courier's starting location, a list of delivery stops, and a traffic window, and returns the stops in …
- Search Algorithms
- Intelligent Agents
- Python Programming
Open courseworkBuild a verifiable portfolio.
Submissions become evidence. Reviewers with shipping experience score against a rubric; the result becomes a credential anyone can verify.
Why Ewance
- 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 - CodeSeniorNew
Cache-Optimize a Graph-Analytics Kernel for a Social Platform
Receive the existing kernel (C++ + OpenMP, around 1,200 lines), the 1.8B-edge graph (CSR format, around 14GB), and target hardware (dual-socket AMD EPYC 9354, 384GB DDR5, 256MB …
- Cache Optimization
- Graph Algorithms
- Memory Hierarchy
Performance Engineering of Software Systems - CodeIntermediateNew
Detect Coordinated Fraud Rings via Link Analysis at a Neobank
You receive 90 days of account, login, and transaction data (around 1.2 million accounts, around 30 million events) plus a labeled set of 80 known fraud rings. Build a multi-rel…
- Graph Analysis
- Community Detection
- Link Analysis
Data Mining and Knowledge Discovery - DesignIntermediateNew
Design an Invoice-Rules Mini-Language for Non-Technical Users
Design a rule mini-language whose grammar (written in Backus-Naur Form, the standard notation for describing grammars) covers boolean logic (and / or / not), comparison operator…
- Abstraction
- Recursion
- Domain Specific Language
Open coursework - AnalysisBeginnerNew
Explain a Credit-Risk Model with SHAP for a Fintech
You receive a trained XGBoost credit-risk model (binary default prediction), the training feature schema (38 features), and a held-out 10,000-sample test set with labels. Comput…
- Shap
- Interpretability
- Fairness Analysis
Explainable and Interpretable AI - ResearchBeginnerNew
Evaluate Speech Synthesis Voices for an EdTech Storyteller App
You will generate 60 audio clips (20 per vendor) covering 4 story genres and 3 emotional tones. Recruit 15 native Spanish speakers via a remote panel (Prolific or local equivale…
- Tts Evaluation
- Listening Studies
- Mos Scoring
Speech Recognition and Spoken Language Processing - 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 - CodeSeniorNew
Rebuild a Fair Single-Selfie Avatar Pipeline at NorthRoom
Using the prior-attempt postmortem (provided), the cohort manifest (provided), the FairFace public image set (provided link), the FLAME face-model resource (provided link), and …
- Digital Humans
- Geometry Processing
- 3d Rendering
Open coursework - CodeSeniorNew
Build and Evaluate an LSM-Tree Storage Engine in Rust
Your analysis task is to complete the engine and produce an evidence-backed comparison of the two compaction strategies. Start from the 'starter-engine' Rust module and finish t…
- Lsm Tree
- Storage Engine
- Rust
Open coursework - AnalysisBeginnerNew
Spectral-Analyze Wearable Sleep Data for a Healthtech Pilot
You receive 30 nights of wearable data per 25 volunteers, with polysomnography-derived ground-truth stages (Wake / NREM / REM). Engineer spectral features (delta, theta, alpha, …
- Spectral Analysis
- Feature Engineering
- Wavelet Analysis
Time Series Analysis and Forecasting - ResearchIntermediateNew
Planning Under Uncertainty for a Last-Mile Delivery Fleet
Build a simulator of the 50-block area with stochastic travel times conditioned on weather and time-of-day. Implement value iteration (for a small state space), MCTS (Monte Carl…
- Planning Under Uncertainty
- Markov Decision Processes
- Monte Carlo Tree Search
Automated Planning - CodeBeginnerNew
Demand Sensing for a 40-Person SaaS Scale-Up
You are a growth analyst at FlowMetrics. Using weekly data on signups, trial conversions, website traffic, and marketing spend, develop a model to forecast monthly subscription …
- Time Series Forecasting
- Regression Analysis
- Python
Forecasting for Decision Making
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.
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