Blinkit SDE-1 Backend | Off-Campus Interview Experience
Summary
I was selected for an SDE-1 Backend role at Blinkit after passing three interview rounds covering DSA, system design, and cultural fit.
Full Experience
I recently got selected for Blinkit SDE-1 Backend through an off-campus opportunity, and I wanted to share my interview experience along with the resources that helped me during my preparation.
Role: SDE-1 - Backend Graduation: 2026 Experience: 6-month internship Location: Gurgaon Interview Process: 3 Rounds Result: Selected
How it started
I received a call from Blinkit HR unexpectedly.
We had a brief conversation around my current work, notice period, location and previous experience. She mentioned that they liked my profile and wanted to schedule an interview.
The process consisted of three rounds:
DSA + Fundamentals -> LLD/System Design -> Cultural Fitment
Round 1 - DSA + CS Fundamentals
The first round was with an SDE-3.
We started with introductions and discussed some of the projects I had worked on.
Before jumping into DSA, the interviewer spent some time testing my understanding of CS fundamentals and backend concepts.
Some of the areas discussed were:
- What happens when a process creates a new thread?
- What is the difference between a process and a thread?
- How does context switching work?
- What is the difference between ArrayList and LinkedList internally?
- What is the difference between clustered and non-clustered indexes?
- When can an index actually hurt database performance?
- How does a database decide whether to use an index?
- What is the purpose of a composite index?
After the fundamentals discussion, we moved to coding.
Problem 1 - Search in Rotated Sorted Array
I was asked to search for a target in a rotated sorted array.
I identified the modified binary search approach and explained how to determine which half of the array remains sorted.
We discussed the edge cases, implementation and complexity before moving to the next problem.
Problem 2 - LRU Cache
The second problem was to design an LRU Cache with efficient get() and put() operations.
I discussed the combination of a HashMap and Doubly Linked List, explained why both were required and then walked through the implementation with a sample sequence of operations.
We also discussed the expected time complexity and some possible edge cases.
The interviewer seemed satisfied with the approach.
We ended the round with some discussion around the team and the kind of work I would be doing.
Round 2 - LLD / System Design
The second round was with a Team Lead.
After introductions and a discussion about my experience, I was given a design problem.
Design a Food Delivery Order Tracking System
We used draw.io to work through the design and gradually built the system.
The round was more about design thinking and trade-offs than writing code.
Some of the areas we discussed included:
Order lifecycle
- API design
- Database schema
- Entity relationships
- Handling order-status updates
- Event-driven communication
- Kafka vs synchronous communication
- Handling high traffic
- Idempotency
- Failure scenarios
- Scalability
- Service boundaries
The interviewer kept digging into the reasoning behind each decision.
For example, if I chose an asynchronous approach, the discussion would move towards:
Why asynchronous? What problem does it solve? What happens if the consumer is down? How would you handle duplicate events?
I felt that there were a few places where I could have explained my design better, so personally I wasn't completely satisfied with this round.
However, I later received the HR call for the final round, so I was happy to know that I had cleared it.
Round 3 - Cultural Fitment
The final round was with the Manager.
This round was much more conversational.
We went through my resume in detail and discussed my previous experience, projects and technologies.
Some of the discussion revolved around:
- A challenging problem I had solved
- How I handled disagreements within a team
- A technical decision I made and its consequences
- How I prioritize tasks
- Things I learned during my internship
- Situations where I had to take ownership
- What I would like to work on going forward
The manager also asked follow-up questions based on my projects rather than simply going through standard behavioral questions.
The discussion lasted around 40 minutes.
At the end, the manager told me that he was happy with my performance and gave me the offer during the round itself.
Definitely one of the best interview moments I've had.
Final Result
Selected for Blinkit SDE-1 Backend!
Compensation Base: ₹24 LPA Performance Bonus: ₹5 L 1st Year Compensation: ₹29 L
I am a 2026 graduate with 6 months of internship experience.
Resources That Helped Me
A big thank you to all the platforms and creators whose content helped me throughout this preparation.
- LeetCode - My primary platform for DSA practice. Solved around 1600 problems and reached a peak rating of 2164.
- Codeforces - Helped me improve problem-solving speed, implementation skills and algorithmic thinking. Solved around 800 problems with a peak rating of 1550.
- Inline Interview - Helped me prepare specifically around my projects, internship experience and the kind of follow-up questions interviewers could ask.
- Striver - Helped me follow a structured DSA roadmap and systematically revise important patterns.
- TLE Eliminators - Useful for improving my algorithmic thinking and competitive programming fundamentals.
- Aryan Mittal - Helped me prepare for LLD, especially around object-oriented design and approaching design problems.
- Gaurav Sen - Helped me understand HLD and system design concepts and think about scalability and distributed systems.
- Engineering Digest - Helped me strengthen my Java, and OOPS concept
A Few Takeaways
My biggest takeaway from the process was that backend interviews require more than just DSA.
You should be comfortable discussing the fundamentals behind the systems you build.
For SDE-1, I'd recommend having a solid understanding of:
DSA OOP OS fundamentals Java internals DBMS LLD Basic HLD
Also, know your resume inside out, prepare every single question that could have been made from your resume, it really helped me a lot.
Anything you've mentioned can become a discussion point.
Don't just know what your project does. Know why you designed it that way, what alternatives existed, what went wrong, and how you would improve it at a larger scale.
That's my interview experience.
Hopefully, this helps someone preparing for their next interview.
Keep solving. Keep building. Keep learning.
All the best!
Interview Questions (3)
Search in Rotated Sorted Array
Given a rotated sorted array and a target value, find the index of the target. The solution should use a modified binary search that determines which half of the array is sorted at each step and narrows the search accordingly. Edge cases such as empty array and target not present should be handled.
Design LRU Cache
Design a Least Recently Used (LRU) cache that supports get(key) and put(key, value) operations in O(1) time. get should return the value if the key exists, otherwise -1. put should insert or update the value and ensure that when the cache reaches its capacity, the least recently used item is evicted.
Food Delivery Order Tracking System Design
Design a system for tracking food delivery orders. The design should cover API endpoints, database schema, entity relationships, order lifecycle management, event-driven communication versus synchronous calls, handling high traffic, idempotency, failure scenarios, scalability, and service boundaries.
Preparation Tips
I prepared using multiple platforms: LeetCode (solved ~1600 problems, rating 2164), Codeforces (800 problems, rating 1550), Inline Interview (focused on project‑based questions), Striver's DSA roadmap, TLE Eliminators for algorithmic thinking, Aryan Mittal for LLD/object‑oriented design, Gaurav Sen for high‑level system design concepts, and Engineering Digest for Java and OOP practice.