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
Optimize Hyperparameters with Bayesian Optimization on a Tight Budget
You receive a B2B-SaaS churn dataset (about 12,000 customer-month rows, 38 features) and a fixed sweep budget of 40 trials per model family. Implement a Bayesian optimizer (Optu…
- Bayesian Optimization
- Hyperparameter Tuning
- Ensemble Methods
Advanced Machine Learning - AnalysisFoundationalNew
Cluster Climate-Tech SMB Customers for a Growth Team
You receive a CSV with company size, industry sub-vertical, country, product features adopted, monthly active users, and lifetime value. Standardize features, decide on a cluste…
- Unsupervised Learning
- Clustering
- Dimensionality Reduction
Machine Learning (Undergraduate) - 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
Site Reliability Engineering - DesignFoundationalNew
Build a Tic-Tac-Toe-Style Game Agent for an Edtech Demo
Implement Connect-Four (7-column, 6-row board) in Python plus a minimax agent with alpha-beta pruning, configurable search depth, and a simple heuristic evaluation function for …
- Game Playing Ai
- Minimax
- Alpha Beta Pruning
Introduction to Artificial Intelligence 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
- 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
- Systems Language Proficiency (Go, Rust, C++)
Blockchain and Decentralized Systems Engineering - CodeIntermediateNew
Add Idempotency Keys to a Payment Webhook System
Read the current Go webhook-sender code and 30 days of duplicate-delivery incident logs. Design the idempotency scheme: server-generated key per event (UUID v7 — time-ordered), …
- REST API Design
- Idempotency
- Webhooks
API Design and GraphQL - AnalysisBeginnerNew
Stress-Test a Hiring-Funnel Model for Bias
You receive a synthetic-but-realistic dataset of 25,000 past applicants with features (years of experience, education tier, prior role tags) and outcome labels (advanced past th…
- Model Evaluation
- Fairness Metrics
- Logistic Regression
Machine Learning (Undergraduate) - CodeIntermediateNew
Design an SAT-Based Verifier for an Autonomous-Vehicle Test Lab
Model a simplified four-way intersection: agent positions, lights, and discrete time steps. Define 5 safety properties in propositional logic (e.g., 'no two agents in the inters…
- Sat Solving
- Logical Inference
- Formal Verification
Artificial Intelligence: Principles and Techniques - Browse challenges
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Strategy Analyst
Frame the business question, model the options, build the recommendation. From market sizing to competitive analysis, this role is where strategy consulting meets in-house decision-making.
- DesignBeginnerNew
Build a Multi-Criteria Vendor Selection Tool for an AI Consulting Firm
You will design a Multi-Criteria Decision Analysis (MCDA, a structured way to score options against weighted criteria) tool that accepts 6-10 vendor options, 6-12 weighted crite…
- Mcda
- Decision Support Systems
- Streamlit
Decision Support Systems and Decision Analysis - CodeBeginnerNew
Ship a Lightweight ML Microservice for an EdTech Reading App
You receive 3 months of session telemetry (around 50M reading events, child-anonymized). Engineer features per session window, train a small classifier (logistic regression base…
- Feature Engineering
- Model Serving
- Containerization
Applied Machine Learning - CodeIntermediateNew
Refactor a Reckless Inadvertent Debt Hotspot
Read the class + git blame to map its responsibilities. Write characterization tests (using approval testing) until you can change behaviour without surprise — target at least 7…
- Refactoring
- Mikado Method
- Characterization Testing
Technical Debt Management - CodeSeniorNew
Min-Cost Max-Flow for Cloud Workload Placement
Receive 30 days of anonymized placement requests (workload CPU/memory shape, affinity rules), zone capacity per day, and cross-zone bandwidth costs. Model the placement as a min…
- Network Flows
- Algorithm Analysis
- Graph Algorithms
Advanced Algorithms Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- CodeSeniorNew
Vectorize a Risk-Calculation Engine for a Mid-Cap Bank
Receive the existing pricer (C++17, scalar, around 600 lines), 2 weeks of representative input data (around 50M paths), the validation harness, and access to an Intel Ice Lake-S…
- Vectorization
- Avx 512
- Simd
Performance Engineering of Software Systems - CodeBeginnerNew
Greedy Algorithm for Delivery-Slot Assignment
Receive 14 days of order data (around 4,800 orders) with timestamps, addresses (already geocoded), and slot preferences, plus rider rosters with shift starts, ends, and max work…
- Greedy Algorithms
- Algorithm Analysis
- Python Or Javascript
Algorithm Design and Analysis - AnalysisIntermediateNew
MCMC for Conversion-Funnel A/B Testing at a Marketplace
You receive 6 weeks of per-visitor funnel data (visit, sign-up, trial start, trial-to-paid conversion) split by variant and by acquisition channel (organic, paid social, paid se…
- Mcmc
- Bayesian Hierarchical Models
- A/B Testing
Probabilistic Machine Learning - CodeIntermediateNew
Temporal Planner for a Robotics Mission Operator
You receive 30 days of mission logs with task lists, time windows, and actual durations. Encode the planning problem with temporal PDDL (PDDL 2.1 durative actions) and solve wit…
- Temporal Planning
- Pddl Modeling
- Simulation
Automated Planning - CodeBeginnerNew
Build a Functional Image-Filter Pipeline for a Photography SaaS
Design a Filter as a function from (pixel matrix → pixel matrix). Build a compose helper that takes a list of filters and returns a single composed filter (function composition)…
- Higher Order Functions
- Function Composition
- Abstraction
Programming Abstractions - AnalysisBeginnerNew
Refit a Pricing Model for an Insurance Comparison Site
You receive 9 months of quote-impression data (about 14 million events) with about 60 features and click labels. Refit logistic regression with elastic-net regularization plus a…
- Regularized Regression
- Feature Interactions
- Calibration
Statistical Machine Learning - CodeIntermediateNew
Forecast Energy Demand for a Nordic Renewable Utility
You receive 5 years of hourly residential-segment demand, hourly weather data (temperature, wind, irradiance), and a calendar of public holidays. Build a probabilistic forecaste…
- Time Series Forecasting
- Probabilistic Modeling
- Feature Engineering
Applied Machine Learning - CodeIntermediateNew
Build a Hybrid Recommender for a Niche Consumer-AI Music App
You receive listening events (around 240 million plays) plus a content embedding per track (audio + curator tags). Build a collaborative filtering model (ALS or implicit-feedbac…
- Recommender Systems
- Collaborative Filtering
- Content Based Filtering
Data Mining and Knowledge Discovery - CodeFoundationalNew
Tune a Pick-and-Place Controller for a Cosmetics Co-Packer
You receive 4 hours of logged trajectories from the existing controller (joint positions, target poses, miss/success labels) and read/write access to the controller config (YAML…
- Motion Control
- Trajectory Tuning
- Robot Kinematics
Robotics - CodeBeginnerNew
Build a Software Rasterizer for a Teaching Engine
Implement a software rasterizer in C++: vector and matrix math (3D and 4D), model/view/projection transforms, viewport mapping, triangle setup, edge-function rasterization with …
- Rasterization
- Geometric Transformations
- 3d Rendering
Introduction to Computer Graphics - AnalysisBeginnerNew
Diagnose Query Failures in an E-Commerce Search Box
You receive 6 months of anonymized query logs (~480 million rows): query string, language hint, results-shown count, top-3 product clicks, and add-to-cart events. Build a notebo…
- Query Log Analysis
- Clustering
- Ir Failure Analysis
Information Retrieval and Search - CodeBeginnerNew
Simulated Annealing for Shift Scheduling at a Hospital
You receive 6 months of anonymized shift demand data, the nurse roster (skills, certifications, contracted hours), and the labor-law hard constraints. Encode the schedule as a 7…
- Simulated Annealing
- Metaheuristics
- Constraint Handling
Evolutionary Computation and Metaheuristic Search
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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