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
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
Open coursework - CodeIntermediateNew
Build a Metered-Billing System for a Usage-Based SaaS
Build an event-ingest API (Express + Redis Streams) that receives usage events with idempotency keys. Aggregate hourly into Postgres rollups using a windowed worker that survive…
- Metered Billing
- Idempotency
- Event Aggregation
Open coursework - CodeBeginnerNew
Case File: Smart-Pointer Refactor of a Game-Engine Module
Work only from the four supplied items: the representative entity-component-system module slice, the before-refactor heaptrack leak readout, the de-identified incident log, and …
- Cpp Programming
- Manual Memory Management
- Pointers
Open coursework - CodeBeginnerNew
Image Search for a DTC Furniture Retailer's App
Use a pretrained vision-embedding model (CLIP ViT-B/32 or DINOv2-small). Index a catalog of around 1,500 furniture images. Curate a small evaluation set of around 50 user-style …
- Image Embeddings
- Vision Transformers
- Image Search
Open coursework 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
- 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
- Go
Data Structures - 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
Open coursework - CodeIntermediateNew
Repository + Unit-of-Work Refactor on an EF Core Codebase
Read the data-access patterns across the 5 bounded contexts (Payroll, Timesheets, Benefits, Org, Reporting) and tag the 12 worst N+1 incidents from the last quarter's traces. Au…
- Repository Pattern
- Unit Of Work
- Design Patterns
Software Design and Design Patterns - ResearchIntermediateNew
Explore the Bias-Variance Trade-off on a Tabular Healthcare Cohort
You receive a 90,000-patient anonymized de-identified tabular dataset (demographics, labs, claims-derived features) and a binary 12-month-readmission outcome. Pick three model f…
- Bias Variance Tradeoff
- Regularization
- Model Selection
Open coursework - Browse challenges
Explore role
Product Manager
Ship product that solves real user problems. Combine user research, prototyping, and stakeholder alignment to turn ambiguous briefs into measurable wins — the role at the centre of modern software teams.
- AnalysisIntermediateNew
Randomized Load Balancer with the Power of Two Choices
Simulate four placement policies on a 24-hour anonymized connection-establishment trace (around 4.1 billion events): (1) random-1, (2) round-robin, (3) P2C with instantaneous lo…
- Power Of Two Choices
- Load Balancing
- Randomized Algorithms
Open coursework - AnalysisSeniorNew
Stochastic Inventory Policy for a Sustainable Fashion Brand
Using historical demand data (provided), fit a demand distribution and determine optimal (s, S) or (R, Q) policy parameters. Consider perishability (seasonal collections) and a …
- Inventory Optimization
- Stochastic Modeling
- Simulation
Open coursework - CodeIntermediateNew
Gaussian Process Regression for Wind Farm Power Curves
You receive 12 months of 10-minute SCADA data (wind speed, air temperature, power output) for 30 representative turbines, plus the manufacturer's published curve. Fit a GP with …
- Gaussian Processes
- Kernel Methods
- Uncertainty Quantification
Open coursework - CodeBeginnerNew
Calibrate a Multi-Camera Rig for Warehouse Robotics
You will design and prototype a calibration workflow using a printed ChArUco board (a chessboard with embedded ArUco markers). You receive a sample dataset of 200 raw frames per…
- Camera Calibration
- Multi View Geometry
- Opencv
3D Vision and Multi-View Geometry 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
- 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
Plan Safe Paths for a Last-Mile Sidewalk Robot
You receive 4 hours of recorded sidewalk traversals with annotated pedestrian tracks, occupancy grids, and a map of the pilot neighborhood. Implement a sampling-based planner (R…
- Motion Planning
- Sampling Based Planning
- Cost Function Design
Open coursework - CodeIntermediateNew
Distributional Embeddings for a Multilingual Legal Search
Use a public multilingual corpus (e.g., MultiEURLEX or a subset of EUR-Lex) plus a small hand-built test set of around 100 cross-lingual query-passage pairs. Fine-tune (or evalu…
- Distributional Semantics
- Multilingual NLP
- Sentence Embeddings
Computational Semantics - CodeIntermediateNew
Localize a Mobile Robot with Particle-Filter SLAM
You receive 4 ROS bags from real customer plants, each containing 2D LiDAR scans, wheel odometry, and ground-truth poses (from a motion-capture cell used only for evaluation). I…
- State Estimation
- Particle Filter
- Slam
Open coursework - StrategyBeginnerNew
Toil Audit + Automation Sprint for a Platform Team
Week 1-2: every team member logs every toil instance for 10 working days (timestamp, category, duration). Categorize using the Google SRE toil taxonomy (manual, repetitive, auto…
- Toil Reduction
- Automation
- Reliability Engineering
Open coursework - DesignIntermediateNew
Add Profile-Guided Optimization to a Production JavaScript Bundler
Design and implement a profile-guided optimization workflow for the bundler using Rust's LLVM-based PGO: an instrumented build, a training run over the eight-project benchmark c…
- Profile Guided Optimization
- Llvm
- Benchmarking
Open coursework - 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) - CodeIntermediateNew
Reproducible Patient-Cohort Analysis for a Pharma AI Vendor
You receive a written cohort definition (type-2 diabetes patients on metformin for at least 90 days, aged 40-70) and a target output: 12-month HbA1c change distribution plus a K…
- Reproducible Analysis
- Cohort Analysis
- Survival Analysis
Open coursework - CodeFoundationalNew
Optimizing Inventory for a Barcelona D2C Cosmetics Brand
You are given a CSV file with 6 months of daily sales data for 20 SKUs, including product name, date, units sold, and current stock level. Your task is to write a Python program…
- Python
- Data Cleaning
- Data Analysis
Open coursework - 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 - AnalysisIntermediateNew
Frame an Energy-Storage Dispatch Decision as a Bayesian Decision Problem
You receive 2 years of hourly spot-price data, 2 years of wind generation data, and a manufacturer's battery degradation model. Frame dispatch as a Bayesian decision problem: mo…
- Bayesian Decision Theory
- Price Modeling
- Back Testing
Decision Making Under Uncertainty - ResearchSeniorNew
Structure Learning for a Causal Network in Fintech Risk
You receive the 60-signal dataset and a short interview summary of risk analysts' beliefs about which signals influence which. Use a hill-climbing structure-learning algorithm w…
- Structure Learning
- Bayesian Networks
- Causal Modeling
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.
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