Idfc First Bank Interviews

Online Assisment:

1. Implementing methods in a Java class (easy to medium)
2. DSA (Hard)

I have solved only 1st question. got shortlisted for F2F interview.

Onsite Interview:

Round 1:

Problem: Given 5 cards in the format "3-H", find the card with the highest value.

refer this: https://leetcode.com/discuss/post/6981837/idfc-frist-bank-backend-dev-3-yr-by-anon-k0xv/

Round 2:

1. Design logging System which must collect the logs and store it for one year. They have focused more on how will I store the logs. also they didn't allowed me to use any of cloud services. I gave the solution like this, storing in the multiple files once it is full we can create new ones and old ones we can compess and store it in disk. also we can have jobs which are runing to delete the files with 1 year old logs.
2. you have a lift class. write a method implementation for move(). which will tell the sensor to go up or down. I wrote a simple method for it.

Final verdict: Rejected

Application Process:

• Applied via: LinkedIn (I think)
• Online Test:
  • 1 DSA question (Easy-Medium)
  • 1 Machine coding question (Implement methods in a given class – Easy-Medium)

A week later, I got an email for an in-person interview scheduled for July 19th.

Pre-Interview Experience:

I had a few questions, so I reached out to the HR. She told me:

“If you reach by 9:30 AM, your interview will start within 15 mins and the process will be done in 3-4 hours max.”

Fair enough. I showed up on time. And then the real experience began.

On-Site Experience:

Reality: ~100+ candidates were crammed into their office, waiting.

⏱️ First Round (Coding):

• Start delayed by ~30-40 mins.
• Problem: Given 5 cards in the format "3-H", find the card with the highest value.
• Simple string parsing – done in 15 mins.
• Called the invigilator, got it evaluated. Most people solved it.

Then we were sent to a different floor for the next round. That’s where things went south.

Disaster Begins:

They collected hard copies of our resumes. Around 8–10 interviewers were picking up resumes at random and interviewing candidates. That would’ve been fine—except there were 100+ people and two panelist took one candidate at a time.

I finished Round 1 by 11:00 AM, and waited around 5–6 hours for my next round. My 2nd round finally happened around 4:30 PM.

Technical Round 1 (T1):

1. Binary Search Problem:

   • Find first occurrence of 1 in a sorted array of 0s and 1s.
   • I used standard BS; then was asked to solve it in 1 iteration.
   • I suggested checking the left after finding 1. Interviewer seemed satisfied, even though this could degrade to O(n) in worst case (all 1s).
   • I didn’t push further.

2. SQL Questions:

   • Write a basic JOIN query on multiple tables – done.
   • Then a GROUP BY query – I used a WHERE clause incorrectly. Interviewer pointed that out. (My bad – I wasn’t prepared for SQL questions.)

3. Design Pattern Question:

   • Asked for a design pattern for a scenario that didn’t map to any real pattern. I gave a custom solution inspired by the Observer Pattern. He nodded.

4. AWS/ECS/Fargate Confusion:

   • I mentioned using ECS with Fargate in a project.
   • He asked: “Why use Fargate and not ECS?”
   • 🤯 Tried to explain Fargate is part of ECS, used for serverless infra, no EC2 mgmt, etc. (P.S - I have cleared associate solution architect certificate by aws)
   • He repeated the question.
   • what i had in mind dude- “if a women is preganant she could have a boy(let's say it farget) or girl (called it EC2) they both will be inside her in any case, you cannot direct get a boy or girl you need women (ECS) for that.It’s like asking why have a boy and not a woman — Fargate and EC2 are launch types inside ECS”

5. I asked how many rounds were left.

   "2 more technical + 1 managerial + 1 CTO"

   Seriously? HR told me the whole thing would be wrapped up in 3–4 hours. How is this level of miscommunication even acceptable?

Final Verdict:

Right after my round ended, the interviewer walked out and informed HR. A minute later, HR told me I was rejected.

All I said was: “Okay.” No regrets. It was a complete waste of time and energy. Panelists were unprepared, disorganized, and asked random, unfocused questions.

Initial screening round

There were 2 OA questions, don't remember what was asked. But AFAIK they were questions around prioirty queue

L1 Interview

I was asked questions about my current project. They ask questions about the architecture, the tech stack used in the project. The objective would be to understand how well do you know your project and if you understand how tech decision are made. This is very important. Considering one scenario in my interview, I was asked what scaling policies were in place for a particular microservice in my project and explain why.

Post that I was asked to design instagram with basic feature, not too much of HLD and LLD, they want to understand how you would pick your database, design your API's and schema.

I was also asked to implement max heap

L2 Interview

I was asked to introduce myself and talk about the project I am working on. Post that I was asked to design a notification banner system like thing for a apartment. Something like the board you see in stock markets where the stock price keep rotating. The question would be very open ended. It is upto you to ask the right questions and design the system.

I was also asked to design class, API and db design for the same. Post that the question was extended for various scenarios.

L3 Interview, CTO round

L3 and CTO round are almost the same. They check your behvaioural aspect, passion for technology, adaptability under pressure and other things.

Result: Cleared all the rounds