I Built a 20-Hour DBMS Interview Prep System Using LLMs — Does It Actually Work?

#interview #database #backend #ai

I used LLMs to build a complete DBMS interview prep system. Here's exactly how - and I want your honest feedback.

Instead of randomly Googling "DBMS interview questions", I ran an experiment using LLMs as my study partner. The results surprised me.

Step 1: Curate the right questions
I asked the LLM: "What are the most frequently asked DBMS questions in senior backend interviews?", not once, but iteratively. I cross-referenced across difficulty levels, topics, and interview formats until I had a distilled list of 100 questions spanning 10 modules - from basics like normalisation all the way to replication, sharding, and MVCC.

Step 2: Find the minimal set of resources
Here's where it got interesting. I gave the LLM my 100 questions and asked: "What is the smallest set of resources that covers all of these with zero overlap?" It mapped every question to exactly 3 resources:

InterviewBit DBMS/SQL articles (free) - for fundamentals + SQL practice
DDIA by Martin Kleppmann (only 5 specific chapters) - for the deep "why" behind transactions, indexing, replication, and storage
LeetCode Top SQL 50 - for hands-on query practice

Total estimated time: ~20 hours. No fluff, no 40-hour courses.

Step 3: Interview-style learning
This was the game-changer. After studying, I asked the LLM to act as an interviewer:

It asked me each question one by one
I answered as if I were in a real interview
It evaluated my response - not just for correctness, but for what a recruiter at a senior level would actually want to hear (trade-offs, real-world examples, depth vs. rambling)

This feedback loop forced me to articulate answers clearly instead of just "knowing" the concept in my head.

Why I'm sharing this:
I genuinely don't know if this approach is better or worse than traditional prep. It felt efficient, but I want to pressure-test it with people who've been on the other side of the table.

A few specific questions for you:

If you've interviewed candidates, does this kind of structured prep actually show in interviews, or does it come across as rehearsed?
Are there blind spots in using an LLM as both curriculum designer and mock interviewer?
What would you add or change to this method?

I'll share the full 100-question study guide with the 7-day plan in the comments if anyone wants it.

Would love to hear what's worked (or not worked) for you.