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 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
Open coursework - AnalysisBeginnerNew
Build a Public Open-Data Dashboard for Urban Mobility
Pull the city's open-data cyclist-collision dataset (10 years of incidents, geocoded). Define a clear before/after window around the protected-lane rollout, control for traffic-…
- Exploratory Data Analysis
- Data Wrangling
- Geospatial Analysis
Applied Data Analysis and Practical Data Science - CodeIntermediateNew
Refactor the Untouchable ReturnsProcessor Class Safely
Start from the representative ReturnsProcessor module extract and the behavior contract supplied in the provided materials, and use the change-and-incident history to decide whe…
- Refactoring
- Mikado Method
- Characterization Testing
Open coursework - DesignIntermediateNew
Design a Continuous Eval Pipeline for an Enterprise RAG Product
Design (and partially build) a continuous-eval pipeline for a RAG system: (1) a structured eval set with at least 50 queries grouped by query class; (2) automated scoring (LLM-a…
- Continuous Evaluation
- LLM Evaluation
- Retrieval Augmented Generation
AI Measurement and Evaluation 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
- ResearchIntermediateNew
Design a Capability Evaluation for an Open-Weights Coding Model
Pick a recent open-weights coding model (e.g., a Qwen, DeepSeek, or Llama variant). Design an evaluation set of around 40 coding tasks across 4 buckets: standard benign coding, …
- Capability Evaluation
- Safety Evaluation
- LLM Evaluation
AI Safety and Alignment - AnalysisBeginnerNew
Audit a Hiring-Screen Classifier for Fairness Across Cohorts
You receive the classifier as a black-box API and a synthetic-but-realistic dataset of 8,000 CVs with imputed demographic proxies (gender, age band, regional cluster) and labele…
- Fairness Evaluation
- Disparate Impact
- Audit Methodology
Trustworthy AI, Robustness, and Safety - 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 - CodeBeginnerNew
Hybrid Search RAG for a HR-Policy Assistant
You receive 1,800 pages of policy documents (Markdown) and 150 labeled question-answer pairs with the gold source policy IDs. Build a hybrid retrieval pipeline: BM25 + dense emb…
- Hybrid Search
- Bm25
- Dense Retrieval
Open coursework - 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.
- CodeIntermediateNew
Build a Custom Kubernetes Operator for a Multi-Tenant SaaS
Receive the current Helm + bash setup, a description of the per-tenant resources to manage, and the cluster details (EKS 1.29, Strimzi for Kafka). Design a TenantPipeline CRD wi…
- Kubernetes Operators
- Crds
- Kubebuilder
Container Orchestration with Kubernetes - DesignIntermediateNew
Spec Trust-and-Safety Eval Harness for an LLM-Powered Customer-Support Bot
You will spec a 6-page evaluation harness covering: (1) jailbreak test set (about 200 prompts across 6 attack families), (2) PII-leakage probes (about 100 synthetic-customer pro…
- LLM Evaluation
- Red Teaming
- Pii Detection
Open coursework - AnalysisBeginnerNew
Optimizing Last-Mile Delivery for a San Francisco Grocery Startup
Your task is to formulate a minimum-cost flow problem for daily delivery routes. Use the provided order data (locations, time windows, volumes) and vehicle specs (capacity, spee…
- Linear Programming
- Network Flow
- Python
Operations Research and Optimization - 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 Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- 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
Design a Force-Controlled Polishing Skill for a Watchmaker
You receive simulated polishing trajectories from the manufacturer's robot, force-sensor logs from 20 master-craftsman demonstrations, and a quality-rubric (mirror finish 1-5) f…
- Impedance Control
- Force Control
- Manipulation
Robotics - 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) - 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
Open coursework - CodeBeginnerNew
Refactor a Tangled Java Pricing Engine With Design Patterns
Start from a provided Java 21 codebase with the legacy PricingEngine class, 38 example fixtures (input cart, expected price), and one failing test demonstrating a bug from last …
- Java
- Design Patterns
- Refactoring
Open coursework - AnalysisIntermediateNew
Model Patient Pathways with a Hidden Markov Model
You receive de-identified monthly summaries for 8,000 diabetic patients, each row coding the count of primary-care visits, specialist visits, ER visits, new medications, and HbA…
- Hidden Markov Models
- Em Algorithm
- Time Series Modeling
Probabilistic Graphical Models - CodeFoundationalNew
Swap a List Scan for a Min-Heap in the Dispatcher
Working only from the materials provided, your job is to make the courier-selection logic faster and to show, with evidence, that it actually got faster. First, read the de-iden…
- Heap Data Structure
- Complexity Analysis
- Python
Open coursework - CodeIntermediateNew
Run a Monte Carlo Tree Search Strategy for a Robotics Pick-and-Place Task
You receive a simulator of the pick-and-place task: a bin with 10 randomly-placed parts, an action space of which part to pick next, and a reward = parts picked per minute with …
- Monte Carlo Tree Search
- Planning
- Simulation
Open coursework - 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…
- LLM Agents
- Multi Agent Collaboration
- Agent Evaluation
AI Agents and LLM-Based Agents - 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), …
- API Design
- Idempotency
- Webhooks
Open coursework - CodeIntermediateNew
Specification-First Refactor of a Payments Module
Read the module, the last 12 months of incidents touching it, and the existing tests. Write a 6-page specification using a precondition / postcondition / invariant format per pu…
- Specifications
- Refactoring
- Characterization Testing
Open coursework - AnalysisIntermediateNew
Benchmark Approximate Nearest-Neighbor Indexes for a Code-Search Startup
You receive a 5 M-vector sample (768-dim, float32) and a 1,000-query labeled benchmark with ground-truth top-50 neighbors per query. Index the same sample in Chroma (HNSW), Qdra…
- Ann Indexes
- Hnsw
- Benchmarking
Vector Databases and Embeddings
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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