IDFC FIRST Bank Senior API Developer Interview Experience (2026) — Mumbai On-site

Everything you've read about banking interviews is true. Except one thing — IDFC FIRST Bank actually cares about modern engineering practices, not just legacy systems.

• Role: Senior API Developer
• Location: Mumbai, Maharashtra, India (On-site)
• Year: 2026
• Timeline: 4 weeks, application to offer
• Rounds: HR Screen → Technical Written → API Design Round → Coding Round → Technical Director Round → HR Final
• Difficulty: Hard — they expect deep understanding of APIs and banking domain
• Outcome: Offer accepted
• Compensation: ₹32 LPA base / ₹38 LPA total comp

The Process

I applied through their careers portal and got a call within a week. What surprised me was that despite being a bank, their interview process felt more like a tech company than a traditional financial institution.

Round 1: HR Screen (30 minutes)

Standard HR round — background check, role expectations, salary expectations. The recruiter was upfront about the role being on-site at their Mumbai office.

"Why IDFC FIRST Bank specifically?"

I talked about their digital transformation initiatives and how they're competing with fintechs. I think mentioning their recent API platform launch helped — it showed I'd done my homework.

Round 2: Technical Written Test (90 minutes)

This was conducted at their office. A pen-and-paper test covering REST vs GraphQL trade-offs, API authentication methods, database normalization, SQL query optimization, and basic algorithm problems.

What caught me off guard — they asked about PSD2 and Open Banking regulations. If you're interviewing for banking roles, definitely brush up on financial regulations.

Round 3: API Design Round (60 minutes)

This was the most unique round I've ever had. They gave me a real banking scenario and asked me to design APIs for it.

"Design APIs for a loan application system. Think about the entire lifecycle from application to disbursement."

I designed RESTful endpoints for customers, loan applications, documents, and disbursement. The architect pushed me hard on security and data privacy.

"How do you ensure only authorized customers can access their loan applications?"

I implemented OAuth 2.0 with scope-based access control. We discussed JWT token validation, refresh token rotation, and how to handle token revocation.

"What about data privacy? Loan applications contain sensitive information."

This led to a discussion about encryption at rest and in transit, PII redaction in logs, and GDPR compliance.

Round 4: Coding Round (75 minutes)

Back-to-back coding on their machines using Java.

"Implement a simple API gateway that can route requests to different backend services based on the path."

I built a basic routing engine with path matching and load balancing. The interviewer then asked me to add circuit breaker functionality and request transformation.

Round 5: Technical Director Round (60 minutes)

This round was with their Technical Director for API platforms. It was a mix of technical deep-dive and leadership questions.

"Tell me about the most complex API system you've designed."

I walked him through a microservices API platform I built, covering service discovery, API versioning, and monitoring.

"How do you handle API versioning when you have breaking changes?"

I explained my approach — URI versioning for public APIs, header-based versioning for internal APIs, and deprecation policies.

The Insider Insight

IDFC FIRST Bank is heavily invested in their API platform as a product. They're not just building APIs for internal use — they're building APIs that external partners and fintechs consume. This means they care deeply about API documentation, developer experience, and API governance.

Compensation

The offer was ₹32 LPA base with a performance bonus that brings total comp to about ₹38 LPA. For a senior role in Mumbai, I thought this was competitive.

Who This Role Is Right For

This role is perfect if you have deep API design and development experience, understand banking domain and regulations, and enjoy building developer platforms.

It might not be for you if you prefer pure product companies over financial institutions or don't want to work on-site in Mumbai.

Frequently Asked Questions

How hard is the IDFC FIRST Bank Senior API Developer interview? I'd rate it hard. They expect deep understanding of APIs, security, and the banking domain.

How long does the IDFC FIRST Bank interview process take? From application to offer, it took me 4 weeks. The on-site rounds require coordination, so scheduling can take time.

What is the IDFC FIRST Bank interview process and rounds? There are 6 rounds: HR screen, technical written test, API design round, coding round, technical director round, and HR final.

How much do Senior API Developers make at IDFC FIRST Bank? For a senior API Developer in Mumbai, expect ₹30-35 LPA base with total comp around ₹36-42 LPA including bonuses and ESOPs.

How to prepare for IDFC FIRST Bank interview in 2025-2026? Study REST API design deeply, including authentication, rate limiting, and versioning. Learn about banking regulations like PSD2 and Open Banking.