I applied to various companies for a full-time role (mostly in systems), and here are some of my On-Campus @ IITD as
well as Off-Campus Online Assessment (OA) and Interview experiences:
It was a 60-minute test on HackerRank. The problem wasn't algorithmic, but rather implementation-heavy. I had to parse a command string and execute the commands, which simulated transactions between users’ bank accounts. It wasn't very difficult, but the implementation was fairly long.
The next round was a 45-minute phone screening on Zoom with one of the engineers. This was a live coding round, which I could attempt either on my local IDE or in their HackerRank sandbox.
Again, it involved an implementation-based problem with 2–3 subparts. Each subpart built upon the previous one.
This round had one programming question (with multiple subparts), which I attempted in C++.
I was given access to an open-source C++ repository and asked to fix two bugs within an hour. I used a debugger and breakpoints to trace and fix the issues.
This was a final, non-technical, 30-minute round with an Engineering Manager.
Some of the questions I recall:
- A deep dive into my internship experience (both technical and non-technical)
- Questions about how I approached my project, its impact, and follow-ups
- My goals as a software engineer for the next two years
- A technically challenging past experience and how I handled it
- Why I believe Stripe is the right career fit for me
Role: C++ Software Engineer
A 90-minute online assessment on CodeSignal, consisting of four easy CP questions.
A 45-minute in-depth systems interview, primarily on OS and C++.
Questions included:
- Use of
inlinefunctions in C++: pros and cons vectorvslist: trade-offs and internal details- Internal working of
malloc, demand paging, etc. - How the kernel allocates memory to user processes
- System calls like
sbrkandmmap
Role: C++ Software Engineer
Two CP questions — one on two pointers (CF 1600 level) and the other was a tricky implementation problem.
- First 10 minutes: resume deep dive and basic project discussion
- Next 20 minutes: CS trivia (virtual memory, process management, page tables, real-time systems, TCP vs UDP, dangling pointers)
- Last 30 minutes: live coding round on HackerRank
I had to debug a dummyvectorimplementation — missing destructor, needed a custom copy constructor, fixed memory leaks, added out-of-range checks, etc.
- First 5–10 minutes: CV discussion
- Then, questions on TCP's internal state machine handling
- Given a code snippet, asked how many times constructors (copy/move/assignment) would be called
- Code exercise related to
char**pointers - Final 20 minutes: Live coding round
- Given a thread-safe queue implementation and benchmark on HackerRank, I had to suggest some optimizations:
- Some of the optimizations:
- Replace copies with move semantics
- Use a condition variable instead of busy waiting
- Make the queue bounded
- Use RAII for locking/unlocking
- Discuss cache friendliness of the underlying container
- Finished in ~45 minutes
Three C++ questions in 120 minutes. One involved finding a bug in a given code snippet; the other two were Leetcode medium-to-hard level.
A 1-hour interview with a senior engineer.
I had to write pseudocode to serialize a struct in binary format and write it to a file.
Follow-up questions included endianness and how to handle it.
Role: Software Engineer
Two CP questions and two systems questions:
- Implement concurrent transactions between two bank accounts using locks
- Remove branching from a given code snippet
The CP problems were roughly CF 1700 level.
2–3 rounds, each focused on CP questions.
15 CS fundamentals MCQs in 20 minutes.
Followed by three non-CP C++ coding questions in 25 minutes.
A long, in-depth systems interview (3–4 hours) covering OS, C++, and parallel programming.
Topics included:
- Smart pointer (
shared_ptr) implementation Stringclass implementation- Memory pool implementation
- Internal workings of virtual functions
- Lock-free data structures (multi-threaded linked list, producer-consumer buffer)
- Endianness detection
- Virtual dispatch
- Memory reordering (hardware/compiler level)
- Lazy allocation and
mallocinternals - Spinlock and contention optimization
- Read-Copy-Update (RCU)
- And several open-ended follow-ups
I made some notes while preparing for these interviews. They can be accessed at this link.