Computer & Information Sciences
Data Science Challenges
Real data-science projects and challenges on Ewance — clean messy datasets, build and evaluate models, and turn raw data into decisions the way a working data scientist does. Solve them to build a portfolio of verified, recruiter-checkable proof you can do the work — not just describe it.
Recommended challenges
- ResearchSeniorNew
Stress-Test Scalable Oversight on a Tool-Using Agent
Design a sandwich-oversight study: pick a task domain where non-expert oversight is plausible but not trivial (e.g., reviewing data-analysis steps, checking small bug fixes, eva…
- Scalable Oversight
- Alignment Research
- Experiment Design
AI Safety and Alignment - AnalysisBeginnerNew
Topic Modeling for Sustainable Fashion Brand's Social Media
You are given a dataset of 50,000 social media posts (text only) mentioning EcoWear. Your task is to preprocess the text, apply an unsupervised topic modeling technique (e.g., L…
- Topic Modeling
- Text Mining
- Lda
Open coursework - CodeIntermediateNew
Parse and Structure Clinical Discharge Summaries
Combine traditional NLP (section segmentation, sentence parsing) with LLM extraction (small open model + structured-output enforcement). Build the pipeline so every extracted fi…
- Structured Extraction
- Clinical NLP
- Parsing
Open coursework - CodeBeginnerNew
Calibrate a Demand Forecast with Bayesian Confidence Intervals
You receive 24 months of weekly demand for 600 SKUs plus the existing XGBoost point predictions. Fit a Bayesian conformal-prediction layer (or, alternatively, a Gaussian-Process…
- Bayesian Inference
- Uncertainty Quantification
- Conformal Prediction
Probabilistic Machine Learning 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
- ResearchSeniorNew
Benchmark Conformal Prediction for a Healthcare Risk-Score
You receive a labeled dataset of about 25,000 patient encounters with the current risk-score's predictions and ground-truth 1-year outcomes. Implement and compare split conforma…
- Conformal Prediction
- Uncertainty Quantification
- Calibration
Statistical Machine Learning - CodeBeginnerNew
Compare MDP Solvers for a Smart-Grid Battery Dispatch Pilot
Model home-battery dispatch as a finite MDP: state is (state-of-charge, hour-of-day, current price tier), actions are charge/hold/discharge with realistic efficiency losses, tra…
- Markov Decision Processes
- Value Iteration
- Policy Iteration
Artificial Intelligence: Principles and Techniques - AnalysisBeginnerNew
Detect Fraudulent Refund Requests for a Mid-Market Marketplace
You receive a labeled dataset with buyer history, seller history, shipping carrier, refund reason text, and outcome label (legit / fraud). Train and evaluate at least two classi…
- Classification
- Model Calibration
- Imbalanced Classification
Open coursework - AnalysisSeniorNew
Cost-Quality Prompt Optimization at Scale
You receive 2,000 labeled code snippets (human rater consensus score 1-5) and budget for at most 8,000 API calls across the optimization run. Run a factorial sweep of 3 prompt s…
- Prompt Optimization
- Cost Quality Tradeoff
- Experiment Design
Open coursework - Browse challenges
Explore role
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.
- DesignSeniorNew
Multi-Region Failover for an Enterprise RAG Service
Design and prototype: (1) a primary-region deployment of the RAG service (vector DB + LLM inference + retrieval API), (2) a passive secondary region with replicated vector store…
- Multi Region Architecture
- Disaster Recovery
- Infrastructure As Code
Cloud Computing for Data and ML - StrategySeniorNew
Run a Mock Algorithmic-Discrimination Investigation for a Hiring-Tech Vendor
As a 3-person team, design and execute a 3-week mock inquiry. Produce: (1) the demand letter you imagine the regulator sending (scope, legal basis, data requested); (2) the vend…
- Regulatory Analysis
- Algorithmic Fairness
- Ai Governance
Open coursework - AnalysisBeginnerNew
Run an A/B Test on Two System Prompts for a Sales Email Assistant
You will (1) design the A/B test (random assignment by rep_id, 50/50 split, 2-week duration), (2) instrument three primary metrics: reply rate (event-based), average tokens per …
- Prompt Evaluation
- Ab Testing
- Metric Design
Open coursework - CodeIntermediateNew
Build an Ensemble Strategy for Marketing-Mix Modelling
You receive 36 months of weekly marketing-spend and outcome data for 8 sample brands. Build a per-brand baseline gradient-boosting MMM model, then build two more base learners (…
- Ensemble Methods
- Stacking
- Time Series Cv
Open coursework Get recognized by recruiters and employers.
Credentials are blockchain-anchored via LearnCoin — tamper-evident, portable, link-shareable on LinkedIn and beyond.
Why Ewance
- CodeBeginnerNew
Build a Fairness Evaluation Harness for a Credit-Score Model
Implement a Python module that, given model predictions, ground truth, and group identifiers, computes demographic parity difference, equal-opportunity difference, predictive-pa…
- Algorithmic Fairness
- Statistical Evaluation
- Python
AI Measurement and Evaluation - AnalysisIntermediateNew
Catastrophic-Forgetting Audit on a Domain Fine-Tune
You receive the fine-tuned 7B chemistry model and its base, plus a benchmark basket (MMLU subset, GSM8K, IFEval, a small instruction-following set). Run all 4 benchmarks on both…
- Catastrophic Forgetting
- LLM Evaluation
- Fine Tuning
Fine-Tuning Large Language Models - CodeIntermediateNew
Build a Federated Learning Prototype Across Two Hospitals
Simulate two sites with non-IID data splits (one site skews older, the other younger). Implement FedAvg using Flower (or PySyft). Run for at least 50 communication rounds; repor…
- Federated Learning
- Fedavg
- Secure Aggregation
Open coursework - AnalysisBeginnerNew
Cost-Optimize an Embedding Pipeline for a Customer Support Knowledge Base
You receive: (a) the current pipeline (full re-embed on any article change, OpenAI text-embedding-3-large, 3,072 dims) with one month of cost logs, (b) a sample of 5,000 article…
- Embedding Models
- Cost Optimization
- Change Detection
Open coursework - CodeIntermediateNew
Build a Vector-Search Backend for an Enterprise AI Knowledge Assistant
You receive a corpus of around 20,000 PDFs (mixed scanned and digital) totalling around 30 GB and a labeled retrieval set of 200 queries with human-judged ground-truth passages.…
- RAG
- Vector Search
- Embeddings
Data Engineering and Big Data Systems - StrategyBeginnerNew
Scope a Demand-Forecasting Model with Operations Stakeholders
You receive recorded interview transcripts (or summary notes) for the three personas, plus a sample of the historical sales data. Map each stakeholder's pain to candidate ML pro…
- Stakeholder Framing
- Ml Problem Scoping
- Metric Design
Machine Learning in Practice - 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 Engineering
Open coursework - ResearchSeniorNew
Quantify Sim-to-Real Gap for a Warehouse Manipulation Policy
You receive a trained pick-and-place policy (PyTorch), the simulation env (Isaac Lab), and access to a real-arm rig (or recorded teleop episodes if hardware is unavailable). Def…
- Sim To Real
- Manipulation
- Experiment Design
Open coursework - AnalysisIntermediateNew
Evaluate an Agent Suite on the SWE-Bench-Style Coding Benchmark
You receive a sandboxed set of 50 small repo-modification tasks (test-passing as the success signal). Run 3 open-source agent frameworks (e.g., OpenHands, SWE-agent, and Aider) …
- LLM Agents
- Agent Evaluation
- Benchmarking
Open coursework - ResearchSeniorNew
Diffusion-Policy Imitation for Bimanual Cooking Tasks
You receive 300 teleoperated demonstrations of a bimanual pour-and-stir task in a Robomimic-style simulator, deliberately including 2 valid solution modes per task (left-pour-ri…
- Diffusion Policies
- Imitation Learning
- Multimodal Action Distributions
Robot Learning - StrategyIntermediateNew
Design a Post-Editing Workflow for a Cross-Border Fintech
You will design a 4-stage MTPE workflow: (1) source-content readiness check, (2) MT generation with the existing vendor, (3) post-editing with tier-based effort (light vs. full)…
- Mt Evaluation
- Workflow Design
- Neural Mt
Machine Translation - CodeIntermediateNew
ReAct Agent for Legal-Research Tool-Use
You receive 30 research questions with paralegal-written gold answers and citation lists, plus stubbed implementations of the 4 tools (you do not need to build retrieval — just …
- React Prompting
- Tool Use
- Agent Design
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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Sponsor a challenge and meet candidates through actual work.
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