Practice Platforms for Data Analysts¶
Where to build skills outside the classroom. Prioritised by value and alignment with this course.
SQL Practice¶
HackerRank SQL (Free)¶
Best structured SQL practice for beginners to intermediate. Problems are organised by difficulty and topic. Start at "Basic Select" and work up to "Advanced Join." URL: hackerrank.com/domains/sql
LeetCode Database (Free / Paid)¶
SQL problems from real company interviews. The free tier has 50+ problems covering JOINs, window functions, aggregation, and subqueries. Filter by "Easy" → "Medium" → "Hard." URL: leetcode.com/problemset/database
SQLZoo (Free)¶
Interactive SQL exercises in the browser. No setup — queries run directly. Excellent for beginners. Complete the first 8 sections before moving to Stratascratch. URL: sqlzoo.net
Stratascratch (Free Tier Available)¶
Real SQL interview questions from companies like Airbnb, Spotify, Uber, Google. Questions have business context — not just "find all rows where X" but "calculate the rolling 7-day average of DAU for Spotify." URL: stratascratch.com
Python and Pandas Practice¶
Kaggle Learn (Free)¶
Micro-courses with interactive notebooks: Python, Pandas, Data Visualisation, Data Cleaning. Run in the browser — no local setup required. Certificate on completion. URL: kaggle.com/learn
Kaggle Competitions (Free)¶
Real datasets with leaderboards. Join the "Getting Started" competitions for structured practice. Even without winning, studying top solutions is invaluable. URL: kaggle.com/competitions
Exercism (Free)¶
Programming exercises with mentorship. The Python track has 130+ exercises from beginner to advanced. Community mentors provide code review. URL: exercism.org/tracks/python
Excel Practice¶
ExcelJet (Free)¶
Not a practice platform but the fastest formula reference. 500+ formula examples. Bookmark for when you need to look something up during a live exercise. URL: exceljet.net
Excel Practice Online (Free)¶
Browser-based Excel exercises. No Excel installation required — great for checking understanding of specific functions. URL: excelpracticeonline.com
Chandoo (Free + Paid)¶
Excel and Power BI tutorials with downloadable practice files. His "Learn Excel" section covers everything from beginner to VBA. URL: chandoo.org
Visualisation Practice¶
Makeover Monday (Free)¶
Every Monday, a new dataset + a chart to redesign. Post your redesign on social media for community feedback. Trains your "what's wrong with this chart" instinct. URL: makeovermonday.co.uk
Workout Wednesday (Free)¶
Weekly Tableau and Power BI challenges with specific requirements to recreate. Good for building technical visualisation skills. URL: workout-wednesday.com
End-to-End Project Datasets¶
Kaggle Datasets (Free)¶
60,000+ public datasets. Good starting points for this course's projects: - Telco Customer Churn (Project 2) - HR Analytics — Employee Attrition (Project 3) - COVID-19 data (Project 4) - Brazilian E-Commerce (Olist) — very clean, large, realistic (Project 5) - IPL ball-by-ball data (Project 7)
data.gov and data.gov.uk (Free, Government)¶
Real public sector data: housing, health, transport, economic indicators. Good for projects you want to add to a portfolio.
UCI Machine Learning Repository (Free, Academic)¶
Classic datasets with good documentation. The Bank Marketing and Online Retail datasets are particularly useful. URL: archive.ics.uci.edu
Maven Analytics (Free)¶
Curated datasets designed for practice. Each comes with a business context and questions to answer. URL: mavenanalytics.io/data-playground
Interview Practice¶
DataLemur (Free)¶
SQL and Python interview questions with solutions. Questions organised by company. Good complement to LeetCode. URL: datalemur.com
Ace the Data Science Interview (Book + Website)¶
500+ interview questions with answers across SQL, Python, statistics, A/B testing, and product analytics.
Pramp (Free)¶
Mock technical interviews with real peer interviewers. Schedule a 45-minute session — you interview someone else and they interview you. URL: pramp.com
Progress Tracking¶
Work through this order:
Beginner (start here): 1. SQLZoo — first 5 sections 2. HackerRank SQL — Easy level (30 problems) 3. Kaggle Python micro-course 4. Kaggle Pandas micro-course
Intermediate: 1. LeetCode Database — Easy (20 problems) 2. Stratascratch — Easy/Medium (20 problems) 3. Kaggle Data Cleaning micro-course 4. Makeover Monday — 4 weeks
Pre-interview: 1. Stratascratch — Medium (20 problems) 2. LeetCode Database — Medium (15 problems) 3. DataLemur — company-specific questions 4. 3 mock interviews on Pramp