Platform Comparison
Data engineering interviews test three core skills: SQL, Python, and data modeling. StrataScratch covers SQL and Python. DataDriven covers all three with adaptive practice and mobile support. Here is how they compare.
Use DataDriven if you want full DE interview coverage (SQL + Python + data modeling), adaptive practice, and a mobile app. Use StrataScratch if you want to practice problems tagged to specific companies. Use both if you want the best of each.
StrataScratch does several things well. If these matter to you, it is worth considering.
StrataScratch lets you solve SQL problems using pandas as an alternative. If your team uses pandas heavily or your interview allows a pandas solution, this dual-language approach is useful for building fluency in both.
Problems are tagged with the company that reportedly asked them. If you have an upcoming interview and want to see what SQL problems a specific company has used, StrataScratch makes that lookup straightforward.
StrataScratch has a sizable collection of SQL and Python problems across many companies and difficulty levels. If you want volume and variety in your practice, the library delivers.
If you are exploring both data science and data engineering roles, StrataScratch covers both with its mix of SQL, pandas, and statistics content. DataDriven focuses only on DE.
Browse the problem bank
Filter by company, difficulty, or topic. Pick a problem that looks relevant.
Solve in SQL or pandas
Write your solution and compare against expected output. Try the pandas version too.
Read the solution explanation
Understand the approach. Check if other users solved it differently.
Pick the next problem manually
You decide what to work on next. No system tells you where your gaps are.
Data modeling? Find another resource
Schema design is not covered. You need a separate tool or study guide.
Start with frequency-weighted SQL
The system serves problems based on what DE interviews actually test most. GROUP BY, JOINs, and window functions come first.
Run code against real databases
SQL and Python execute in a sandboxed environment. See real results, real errors.
Weak spots surface automatically
The adaptive system tracks your accuracy per topic and routes you to what needs work.
Practice schema design interactively
Build tables, define relationships, reason about normalization. No other platform has this.
Practice on your phone
Full iOS app with real execution. Same challenges, same code keyboard, anywhere.
DataDriven
SQL challenges covering the topics that dominate real DE interviews. Deep practice on GROUP BY, JOINs, window functions, CTEs, NULL handling, and multi-step business logic, weighted by how often each concept actually appears.
StrataScratch
SQL problems sourced from real interview questions. Good coverage of common patterns. Problems tagged by company and difficulty.
DataDriven
Python challenges focused on data engineering: data structures, ETL patterns, string processing, file I/O. Code executes with real test cases in a sandboxed environment. More than half of DE interviews include a Python round.
StrataScratch
Python problems focused on data manipulation with pandas. Good for data science Python, less coverage of DE-specific Python patterns.
DataDriven
Interactive schema design practice. Normalization, star schemas, SCD types, cardinality reasoning. Roughly a third of DE interviews include a dedicated modeling round, and this is the only platform with hands-on practice for it.
StrataScratch
No data modeling content. Focused entirely on SQL and Python coding problems.
DataDriven
All SQL runs against a real database. All Python executes with real test cases. You see actual query results and error messages.
StrataScratch
SQL runs against a database with expected output comparison. Python also executes. Both platforms provide real execution.
DataDriven
Tracks performance across every topic. Identifies weak spots automatically and focuses practice on the areas where you need the most work.
StrataScratch
Problems are tagged by difficulty (Easy/Medium/Hard). No adaptive system that personalizes based on your performance.
DataDriven
Full iOS app with real code execution. Practice SQL and Python on your phone with the same execution environment as the web app.
StrataScratch
No mobile app. Web-only platform.
DataDriven
Challenges designed to match real DE interview patterns. Based on DataDriven's analysis of verified interview data, with topics weighted by how frequently they appear in actual rounds.
StrataScratch
Problems tagged with the company they were reportedly asked at. Useful for targeting specific interview loops.
DataDriven
Free trial. $9.99/month or $99.99/year.
StrataScratch
Free tier with limited problems. Premium plans start at $29/month.
Real SQL execution. Real Python test cases. Interactive schema design. Adaptive practice that finds exactly where you need work.