I started with users and workouts and thought I was on the right track, but then realized I had no clean way to model exercises within a workout without creating a mess of junction tables.
Start by clarifying the scope and key features of the fitness app (e.g., user profiles, workouts, tracking, social features). Then design a normalized relational schema that balances flexibility, scalability, and performance, explicitly discussing trade-offs and indexing strategies.
Pro tip: Demonstrate awareness of read-heavy vs. write-heavy patterns and propose denormalization or caching for frequently accessed data like activity feeds, showing you think beyond just tables.
Ask about core features, expected scale, and data access patterns to define the schema's scope and priorities.
List main entities (User, Workout, Exercise, ActivityLog, etc.) and define their relationships (one-to-many, many-to-many).
Create normalized tables with primary and foreign keys, ensuring data integrity and avoiding redundancy.
Add indexes on frequent query columns, consider partitioning for large tables, and discuss denormalization for read-heavy features.
Explain choices like SQL vs. NoSQL, normalization vs. denormalization, and how the schema supports future growth.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.