Data Science
Data Scientist
Somewhere between a researcher and a software engineer sits the data scientist, the person who answers questions a company didn't quite know how to ask. The work blends statistics, programming, and a stubborn refusal to accept easy explanations.
One week you might design an experiment to measure whether a new feature actually causes more usage, the next you might build a forecasting model that shapes next year's hiring plan. Students who enjoyed both math class and writing essays tend to thrive.
Tools like Python and PyMC become daily companions, but the deeper skill is asking the right question. Excellence looks like a recommendation that holds up six months later because the underlying causal reasoning was sound.
Problem framing + experimental design + defending methodology to non-technical audiences are exactly the parts of the role AI augments but doesn't replace.
US$134,855 median salary in United States¹
- CodeIntermediateNew
Detect Coordinated Fraud Rings via Link Analysis at a Neobank
You receive 90 days of account, login, and transaction data (around 1.2 million accounts, around 30 million events) plus a labeled set of 80 known fraud rings. Build a multi-rel…
- Graph Analysis
- Community Detection
- Link Analysis
Data Mining and Knowledge Discovery - 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 - ResearchIntermediateNew
Detect Coordinated Inauthentic Behavior on a News-Sharing Network
You receive a 60-day sample of about 6 million posts mentioning a recent election, with account metadata (creation date, posting times, follower graph). Design and prototype a C…
- Network Analysis
- Anomaly Detection
- Near Duplicate Detection
Social Network Analysis and Web Science - CodeIntermediateNew
Link Prediction for a B2B SaaS Account-Expansion Engine
You receive a CSV of around 80,000 accounts (existing customers + prospects) with attributes (industry, size, tech stack, geography) plus 18 months of marketing-touch and conver…
- Link Prediction
- Node Embeddings
- Node2vec
Machine Learning on Graphs 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
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
Probabilistic Machine Learning - 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
Applied Data Analysis and Practical Data Science - CodeIntermediateNew
Train a GNN for Fraud-Ring Detection at a Payments Fintech
You receive an anonymized transaction dataset (around 120,000 merchants, around 4 million transactions over 12 months, around 2% labeled fraud) and the team's LightGBM baseline.…
- Neural Networks
- Graphsage
- Fraud Detection
Machine Learning on Graphs - AnalysisIntermediateNew
Forecasting Churn for a SaaS Scale-Up
You are a data scientist intern at TaskFlow. Using the provided dataset, perform feature engineering and build a logistic regression or decision tree model to predict churn. Ide…
- Data Analysis
- Regression
- Classification
Data Analytics for Business - 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
Build a Bayesian Credit-Scoring Model for an Emerging-Markets Fintech
You receive an anonymized snapshot of about 30,000 historical applications with features (income proxy, tenure on platform, prior loans, region) and the binary default outcome. …
- Bayesian Learning
- Credit Scoring
- Model Evaluation
Advanced Machine Learning - AnalysisIntermediateNew
Exploration Strategies for a Recommendation Bandit
You receive 60 days of anonymized impression/click logs covering around 200 content items and user features (cohort, listening history bucket). Build a contextual-bandit simulat…
- Contextual Bandits
- Thompson Sampling
- Ucb
Reinforcement Learning - 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
Mine Health-Forum Posts for Symptom Trend Signals
You receive 6 months of crawled public posts (~400,000 posts, already cleaned of usernames) and access to a UMLS API for normalisation. Build a pipeline that does (1) symptom ex…
- Text Mining
- Biomedical NLP
- Umls Normalization
Linguistic Engineering and Language Technologies 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
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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Industry teams behind a decade of practitioner briefs
Hiring from this pool?
Sponsor a challenge and meet candidates through actual work.
Industry teams can shape briefs around the skills they hire for, then evaluate students on rubric-scored deliverables — not resumes.
¹ Median annual salary computed from the salary histogram of 50 current Adzuna job postings for "Data Scientist" in United States, fetched May 2026. Skills come from the disciplines tagged on live Ewance challenges for this role.
Portrait: Photo by Jake Nackos on Unsplash.