Blinkit Interviews

Received an HR call explaining the role and interview structure. Scheduled Round 1 (Technical). The first round was DSA-based but with a system-design flavor. The main problem was to design an oncall system, divided into multiple sub-parts. The focus was on data structures choice, handling edge cases, scalability, and clarity of logic. I first explained my approach verbally, discussing how I would model the system, what data structures I would use, and how different operations would work. After that, the interviewer asked me to write the complete code based on the approach I explained. Key takeaways: clearly explaining your thought process is very important, even system-design-like problems can be DSA-heavy, and be prepared to convert your design into clean, working code.

My interview with Blinkit for the SDE-2 role started with a brief introduction followed by a discussion about my current project. The interviewer then asked a technical question about finding the minimum possible distance from a source to a destination in a weighted directed graph, with the condition that we can add at most one edge to the graph. The expected time and space complexity was E * log V. I was able to solve this question with the help of a hint from the interviewer. Since we were out of time, he asked me not to code the solution.

After that, the interviewer asked about the advantages of cache. I explained that cache is used for faster retrieval, but then he followed up with another question: "Assume we have infinite cost. Why can't we just replace a database with a cache?" I was not able to answer this question. The interview ended with a rejection, and I'm wondering if not being able to answer the last question was the reason for the rejection.

Round 1 DSA

Problem: Kth Largest Element in a Stream (LC #703)

As interviewer told that there would be just one problem in this round so i started with bruteforce sorting solution just to pass time and then optimized it to best solution using min-heap. Coded the solution cleanly with proper handling of all cases. Interview seemed to go well with no negative feedback. Still got rejected the next day without explanation. Frustrating when you solve everything correctly but still get rejected. It unnecessarily waste time. Anyone else experience this with Blinkit?

Just a few days ago, I wrapped up one of the most exciting interview processes I’ve ever been part of — and today, I'm thrilled to share that I've accepted an offer from Blinkit as an SDE-1! 🚀

Total years of experience - 2.3 years.

Blinkit’s interview process is short, crisp, and focused — just 3 rounds:

• DSA Round
• System Design
• Hiring Manager Round

Here’s a breakdown of my experience 👇

⚙️ Round 1: DSA + Kafka Curiosity

The interview started off with the interviewer spotting Kafka multiple times in my resume (and rightly so, I’ve worked extensively on it). This sparked a discussion around:

• How I used Kafka in my previous projects
• How I handled fault tolerance, load balancing, and failures
• Real-world use cases I built around it

Then came the DSA part — a story-based problem that was a blend of House Robber II + Combination Sum. I walked through both recursive and memoized approaches, and the interviewer was happy with the way I structured and explained my thought process.

🛠️ Round 2: System Design

This was taken by an SDE-3 who was deep into systems thinking. He gave me an open-ended but realistic problem:

Design a system that can collect credentials from multiple financial apps, scrape data, process it, and generate analytics for both users and admins.

As we discussed, he dynamically added admin-level analysis to the requirements — and I had to adapt the architecture on the fly. It was tricky but fun!

⚠️ Pro Tip: Practice using tools like draw.io or Alphine beforehand — I usually use whiteboards but had to quickly adapt during the call.

We extended beyond time as I kept pitching scalable ideas (analytics with pie charts, generic services, etc.). That persistence paid off — we ended up discussing:

• Elasticsearch and inverted indexes
• Database tradeoffs
• Master-slave setups and caching strategies

The interviewer appreciated the effort and told me, "You had misses, but you didn’t give up — that’s what mattered." ❤️

👨‍💼 Round 3: Hiring Manager (but it felt like a Kafka deep-dive)

Expected a cultural fit round? Well, surprise! The manager saw Kafka again on my resume and deep-dived into real-world async problems Blinkit is facing right now while processing orders.

We discussed:

• Async order processing challenges
• Kafka optimization strategies
• Frontend checks + backend resilience
• Scenarios I handled in production

He ended by saying:

"Kafka is our backbone, and your understanding of it is solid. I’m impressed."

💬 We even touched on comp discussion at the end — but more on that in a separate post 😉

✨ Same day offer. Offer accepted. I’m super excited to be joining Blinkit and can’t wait to build impactful systems with the team!

If you’re preparing for interviews or working with Kafka, feel free to drop a comment or message — always happy to chat tech 💬

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