Yesterday was intense.

I had three interviews in one day two technical rounds and one unexpected HR-turned-coding round. both for backend roles. Here's a breakdown of what happened, what I learned, and some honest truths about hiring, luck, and connections.

Interview 1 – Smooth Sailing with a Touch of Zod & MongoDB

This one felt good from the start. The interviewer and I introduced ourselves and got comfortable, then he shared a short backend task doc and I can use google or docs for completing the task but no use of AI and also I have to complete this in 30-35min:

• CRUD for Tasks:
  • Create task
  • Get all tasks
  • Update task (PUT)
  • Delete task

Pretty standard REST API stuff.

I used:

• MongoDB (local setup via Docker)
• Postman to test the routes
• Zod for schema validation as middleware

I completed the task correctly. After that, he asked some follow-ups like:

• "How would you get only the tasks that aren’t completed?"

Honestly, I blanked on the MongoDB syntax and gave an example from Postgres with Prisma. He was cool with it.

Then we went deeper:

• Security questions - How to protect routes if someone gets access?
• NoSQL storage - I mentioned Redis.
• We discussed Redis pub/sub, queues, and rate limiting for DDoS protection.

The whole thing felt more like a conversation than a grilling. I liked it.

Interview 2 – DSA Surprise & IITIANS Everywhere

Anyway, this round was with a company where all founders and most candidates were from IIT. I wasn’t. Felt a bit out of place, but I kept going.