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.
- ResearchIntermediateNew
Detect Coordinated Inauthentic Behavior on a News-Sharing Network
You receive a 60-day sample of about 6 million posts mentioning a recent election, with account metadata (creation date, posting times, follower graph). Design and prototype a C…
- Network Analysis
- Anomaly Detection
- Near Duplicate Detection
Social Network Analysis and Web Science - CodeBeginnerNew
Design a Race-Free Cache for a Read-Heavy Service
Implement a thread-safe LRU-bounded cache in Java (or Go — your choice, defend it) with: read-write lock or copy-on-write semantics, get-or-load pattern with single-flight to de…
- Concurrent Data Structures
- Race Conditions
- Single Flight
Concurrent and Parallel Programming - CodeSeniorNew
Profile and Tame a P99-Latency Tail for an Ad-Auction Service
Receive the bidder source (Go, around 22,000 lines), production traces (eBPF + flame graphs from 30 minutes of peak traffic), and the host config (NUMA-2 socket, 96 cores, 384GB…
- Performance Optimization
- Ebpf
- Systems Language Proficiency (Go, Rust, C++)
Performance Engineering of Software Systems - 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 Basics
Data Mining and Knowledge Discovery 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
- DesignIntermediateNew
Wireless Sensor-Network Design for a Vineyard Microclimate Study
Spec the network: 60 LoRaWAN sensor nodes + 2 gateways (TheThingsStack indoor + outdoor gateway choice), star topology with possible relays. Node hardware: ESP32 + LoRa + sensor…
- Sensor Networks
- Embedded Systems
- Lorawan
Internet of Things and Cyber-Physical Systems - CodeBeginnerNew
Apply SOLID to a Java Reporting Service for a Renewable Energy Startup
Receive the legacy ReportService, 4 sample report templates (Daily Output, Monthly P&L, Annual Availability, Curtailment), and 22 fixtures (input dataset, expected report). Refa…
- Python Or Javascript
- Solid Principles
- Refactoring
Object-Oriented Programming and Design - AnalysisBeginnerNew
Evaluate Speech-to-Text Quality for a Contact-Center Analytics Vendor
You receive 200 anonymized call-recording snippets (2-4 minutes each, ~67 per language) with reference transcripts plus a domain glossary of about 600 product terms. Run all thr…
- Speech Recognition
- Sequence Models
- Model Evaluation
Machine Perception - AnalysisBeginnerNew
Interpretable-by-Design GAM for an Insurer's Claims Triage
You receive an anonymized claims dataset (around 60,000 claims, target: log reserve), a feature schema (22 features), and an existing LightGBM baseline (held-out R^2 of 0.78). T…
- Generalized Additive Models
- Ebm
- Interpretability
Explainable and Interpretable AI - Browse challenges
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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.
- 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
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 - CodeIntermediateNew
Build a CodeQL Query Pack to Catch Logging-of-PII
Use CodeQL to write queries for Java and Python that detect data flow from PII sources (request parameters, database columns marked PII, user-profile fields) into logging sinks …
- Static Analysis
- Codeql
- Data Flow Analysis
Program Analysis - 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
Time Series Analysis and Forecasting Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- CodeBeginnerNew
Knowledge-Graph Recommender for a Niche Online Bookstore
Model the catalog as a knowledge graph (nodes: books, authors, genres, themes, eras, awards; edges: wrote, in-genre, has-theme, won, similar-to). Use Neo4j or a simple Python in…
- Knowledge Representation
- Knowledge Graphs
- Python Or Javascript
Introduction to Artificial Intelligence (CS Elective) - CodeIntermediateNew
Implement a Persistent Immutable List for a Collaborative-Editing Startup
Implement in Python (or TypeScript / Kotlin). Build a persistent immutable list with operations: get, set, append, pop, slice, concat. Use structural sharing (32-way vector trie…
- Data Abstraction
- Recursion
- Persistent Data Structures
Programming Abstractions - CodeIntermediateNew
Multi-Agent Research Assistant for Biotech Patent Review
You receive 20 historical patent applications with the firm's own prior-art memos as ground truth. Design and build a 3-agent system: (a) Searcher — issues queries to a patent-s…
- Ai Agents
- Multi Agent Collaboration
- Agent Evaluation
AI Agents and LLM-Based Agents - AnalysisBeginnerNew
Audit a Climate-Tech Sensor Dataset for Production Readiness
You receive 18 months of raw sensor readings from 1,200 sensors (about 800M rows), plus a sensor-metadata table (location, firmware version, deployment date). Profile the data f…
- Data Quality Audit
- Data Profiling
- Time Series Analysis
Applied Data Analysis and Practical Data Science - 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 - DesignBeginnerNew
Detect Sensor Drift for a Field Inspection Robot Fleet
You receive 60 days of telemetry from 12 robots, including IMU readings, camera exposure stats, and the inspection-quality scores produced downstream. Define drift signals (roll…
- Anomaly Detection
- Change Point Detection
- Sensor Fusion
Robot Perception and Autonomy - 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 Or Javascript
Introduction to Artificial Intelligence (CS Elective) - CodeBeginnerNew
Tune a Recommender for an EU Streaming Music App
Use the public Last.fm-360k or similar dataset (anonymized listening histories) as a stand-in. Implement a baseline matrix-factorization recommender, then a hybrid that adds tra…
- Recommender Systems
- Feature Engineering
- Model Evaluation
Applied Machine Learning - DesignIntermediateNew
Build a Feature Store for a Fintech Fraud Team
You will design a feature-store layer covering 12 representative fraud features (account-level, merchant-level, transaction-level), with both batch (Spark) and online (low-laten…
- Feature Stores
- Data Pipelines
- Apache Spark
Machine Learning at Scale - CodeIntermediateNew
Simulating Queueing for a 40-Person SaaS Support Team
Build a discrete-event simulation of the ticket handling process: tickets arrive randomly (Poisson), are triaged, then assigned to specialists (tier 1 and tier 2). Calibrate usi…
- Simulation
- Queueing Theory
- Python Or Javascript
Operations Analytics and Optimization - CodeFoundationalNew
Replace a Naive List with a Heap in a Delivery Dispatcher
Read the current dispatcher source (around 400 lines of Python). Identify the linear scan and the operations that touch it (insert, decrease-key on a re-scored courier, extract-…
- Heap Data Structure
- Complexity Analysis
- Python Or Javascript
Data Structures - 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
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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