Grokking Database Fundamentals for Tech Interviews
How databases actually work underneath: storage engines, indexes, transactions, isolation levels and the relational versus non relational choice. The layer that makes system design answers defensible instead of hand waved.
Course
System Design
Design Gurus
2 weeks
Beginner
Subscription
What it covers
The machinery. How rows are stored on disk, what a B tree index really costs on write, what a transaction guarantees and what an isolation level quietly gives up, how replication lag produces reads that look impossible, and where document, key value, column and graph stores genuinely fit.
Why it changes design interviews
Most candidates say "I would use a NoSQL database here" and cannot answer why. Understanding the storage layer turns that into a defensible statement about access patterns and consistency requirements, which is the difference between a passing and a strong design round.
How to use it
Run the experiments. Add an index and watch the query plan change; open two transactions and watch an isolation anomaly appear. Ten minutes of that beats an hour of reading.
Best for: engineers whose database knowledge stops at writing queries.
Ready to start?
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Stuck on something specific?
Writing only gets you so far. If you want an answer to your situation rather than the general case, book a session and we will work through it together. Every session is free; a few slots open each week.
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