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.
- 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 - AnalysisBeginnerNew
Diagnose Churn Drivers for a B2B SaaS Workflow Tool
You receive three CSV exports: 18 months of weekly product-usage events for about 1,800 accounts, the full support-ticket history, and account firmographics (industry, size, pla…
- Exploratory Data Analysis
- Data Wrangling
- Feature Engineering
Applied Data Analysis and Practical Data Science - CodeIntermediateNew
Code Review and Refactoring of a Legacy E-Commerce Module
You are given a codebase (Java/Spring Boot) of the order module. Perform a static analysis, document issues (e.g., god classes, tight coupling), and write a refactoring proposal…
- Code Review
- Refactoring
- Python Or Javascript
Software Engineering and Quality Assurance - DesignSeniorNew
Design an End-to-End Encrypted Messaging Protocol
Read the Signal protocol specifications (X3DH, Double Ratchet) and the team's current architecture (server-stored unencrypted messages). Design an E2EE protocol covering: identi…
- Applied Cryptography
- Protocol Design
- Systems Language Proficiency (Go, Rust, C++)
Applied Cryptography 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
- AnalysisBeginnerNew
Mine Association Rules for a Grocery Retailer's Promo Strategy
You receive 6 months of basket-level transaction data (around 22 million baskets, around 18,000 SKUs) plus a category taxonomy. Run association-rule mining (Apriori or FP-Growth…
- Association Rules
- Market Basket Analysis
- Apriori
Data Mining and Knowledge Discovery - CodeIntermediateNew
Edge-Inference Pipeline for a Smart-Factory Vibration Monitor
Architect a pipeline that runs on an ESP32-S3 + STM32 combo (provided): (1) sample 3-axis accelerometer at 3.2 kHz, (2) compute windowed FFT features on-device every 1s, (3) run…
- Edge Computing
- Embedded Systems
- Sensors And Actuators
Internet of Things and Cyber-Physical Systems - CodeSeniorNew
Build a Secure Multi-Party Computation Demo for Cross-Bank Fraud Detection
Pick MP-SPDZ as the MPC framework. Build a 4-party demo computing two protocols: (1) private set intersection of suspicious-account IDs across banks, (2) joint aggregate (count …
- Secure Computation
- Mpc
- Cryptography
Privacy-Enhancing Technologies - ResearchIntermediateNew
Compare Kernel Methods to Trees on a Genomics Classification Task
You receive a curated benchmark of about 12,000 labeled variants with ~120 numerical + ~40 string features. Fit kernel SVMs (RBF, polynomial, string), random forest, and XGBoost…
- Kernel Methods
- Svm
- Tree Ensembles
Statistical Machine Learning - 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.
- CodeIntermediateNew
Lambda-Calculus Semantic Parser for a Math-Tutor EdTech
Define a small typed lambda-calculus representation for linear equations and a small set of word-problem templates (rate, age, mixture). Build a parser that maps surface express…
- Semantic Parsing
- Lambda Calculus
- Symbolic Reasoning
Computational Semantics - CodeIntermediateNew
LLM-Powered FAQ Chatbot for 40-Person SaaS Scale-up
You have access to TaskFlow's internal documentation, help articles, and a sample of 500 support tickets. Your task is to build a retrieval-augmented generation (RAG) pipeline: …
- Large Language Models
- RAG Architectures
- Information Retrieval
Text Analytics and Natural Language Processing - AnalysisBeginnerNew
Build a Reproducible Pricing Analysis for a DTC Skincare Brand
You receive 24 months of order-line data (around 480,000 lines), a Shopify-style customer export, and a discount-code log. Build a Python pipeline that produces: SKU-level price…
- Data Wrangling
- Exploratory Data Analysis
- Cohort Analysis
Applied Data Analysis and Practical Data Science - CodeIntermediateNew
Tune a Multicore Pipeline with NUMA-Aware Sharding
Receive the current worker (Rust, around 8,000 lines, uses rayon for its parallelism), the host (2-socket AMD EPYC 9354, 64 cores total, 384GB DDR5), and a benchmark query workl…
- Parallel Performance
- Numa
- Systems Language Proficiency (Go, Rust, C++)
Advanced Concurrency and Parallel Computing 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
- AnalysisBeginnerNew
Spectral Clustering for an Urban-Mobility Operator's Network
You receive 6 months of anonymized O-D trip data (around 4 million trips, around 8,000 virtual stations), the current 9 hand-drawn zones, and the operations team's KPIs (rebalan…
- Spectral Methods
- Spectral Clustering
- Graph Laplacian
Machine Learning on Graphs - CodeBeginnerNew
Prototype a Multimodal Visual-Question-Answering Demo
You will use a small open-source vision-language model (e.g., LLaVA-1.5-7B or PaliGemma) and prompt-engineer it for the warehouse-VQA task. Build a Gradio web demo. Construct a …
- Vision Language Models
- Multimodal Perception
- Prompt Patterns
Machine Perception - 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 Or Javascript
Machine Learning (CS Elective) - 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
Open-Domain QA over Product Documentation
You receive a snapshot of the documentation (Markdown) and 120 real support questions with the URLs of pages containing the answer. Build an open-domain QA pipeline: chunk the d…
- Open Domain Qa
- Passage Retrieval
- Reading Comprehension
Question Answering and Conversational Systems - CodeBeginnerNew
Implement an Expression Evaluator Using Recursion and Higher-Order Functions
Implement in Python (or TypeScript). Build a tokenizer, a recursive-descent parser producing an abstract syntax tree (AST), and a tree-walking evaluator. Use higher-order functi…
- Recursion
- Higher Order Functions
- Parsing
Programming Abstractions - CodeIntermediateNew
Refactor a God-Object Order Service with Strategy + Command
Read OrderService and the last 18 months of bug tickets touching it. Author a 5-page design document showing the current class diagram, the target Strategy-per-order-type + Comm…
- Design Patterns
- Refactoring
- Strategy Pattern
Software Design and Design Patterns - CodeBeginnerNew
Responsive Web Redesign for SaaS Scale-up
You are to redesign the TaskFlow website's homepage, pricing page, and a new 'Enterprise' landing page. The redesign must be responsive (mobile-first) and built with HTML/CSS/JS…
- Html & Css
- Html & Css
- Python Or Javascript
Web and Mobile Application Development - ResearchSeniorNew
Probabilistic Numerics for an ODE-Constrained Battery Model
You receive 12 months of charge/discharge cycle data for 50 battery packs from a delivery-van fleet, plus the existing single-particle ODE degradation model (Python). Use a prob…
- Probabilistic Numerics
- Bayesian Inference
- Ode Modeling
Probabilistic Machine Learning - CodeSeniorNew
Multilingual RAG for a European Customer-Support Knowledge Base
You receive 6,000 documents in 4 languages (mix of FAQs, parts catalogs, repair procedures) plus 120 labeled queries (30 per language) with gold source documents. Build a multil…
- Multilingual RAG
- Cross Lingual Retrieval
- Multilingual Embeddings
Retrieval-Augmented Generation - CodeIntermediateNew
Design a Lock-Free Concurrent Queue for an Event Bus
Implement an MPSC (multi-producer single-consumer) ring-buffer queue in Go using atomic operations only — no mutexes. Prove correctness with the Go race detector across 8 produc…
- Concurrent Data Structures
- Lock Free Programming
- Systems Language Proficiency (Go, Rust, C++)
Data Structures - 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
Social Network Analysis and Web Science
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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