My FlexTrade Interview Experience
Role: Software Developer / Associate SDE | Batch: 2027 | Branch: Computer Engineering (PICT) | Mode: On-campus
TL;DR: The OA had 2 DSA questions, followed by 4 rounds (2 technical, a director's round, and HR). Along the way I was told no for SDE, offered Technical Analyst, and then selected for SDE anyway when a new position opened. Skills got me into the room, but luck decided a lot of the rest. Read to the end for the mindset stuff.
Online Assessment
It was on HackerEarth or something similar. There were 2 coding questions in 1 hour, with no MCQs.
Q1 (easy, bit manipulation): Sort an array in ascending order by the number of set bits in each number. I solved it fully.
Q2 (medium, greedy/arrangement): I don't remember the exact statement. I didn't crack the full approach, but pattern-matching a greedy idea got me 9/15 test cases.
Results and the shortlist came about 3-4 days later. I didn't research the OA pattern beforehand, and it still worked out, but I'd still say look it up.
Interview Rounds
There were 4 rounds: 2 technical, 1 director's (not everyone gets this one), and 1 HR.
Heads up on timing: My interview was scheduled for 2 PM and started around 3-3:30. There are lots of candidates and few panels. Expect to wait 1-1.5 hours for the first round and 30-60 minutes between rounds. Bring water and a snack. I survived on caffeine gum, but I can control my hunger, and a few people who couldn't visibly dipped by the later rounds.
Technical Round 1 (~40 min)
One interviewer, very friendly.
Implement a stack using an array in an online compiler. They prefer C++, but let me use Java when I asked. Push, pop and size, with a few example cases. About 15 minutes.
Project questions. My project was RAG-based, so they asked which LLM and why, tokens, and the vector DB. They kept it to basics.
OOP: the four pillars with examples, and why OOP is preferred.
I asked for feedback at the end and he said there was nothing to improve.
Technical Round 2
Two interviewers.
Circular linked list from scratch, then delete the nth node from the end. It took me 10-15 minutes. We LeetCode people rarely write the whole node and list class from zero, so this felt harder than it should have. I checked edge cases (n equal to the length, a single node) and it worked.
Basic system design. "A server is getting lots of requests, how do you handle it?" I said horizontal scaling and he said no, there's only one server. What he wanted was a rate limiter, implemented with a data structure.
I mentioned threads, and he said not to overcomplicate it.
I did a queue-based simulation with a fixed window (size 5 or 10) and walked through the operations. Finding the approach was the hard part, and the implementation was easy.
They seemed happy, and I'd say it went about 85-90% well. The remaining 10% was them not following my explanation in a few places.
Director's Round
They called me in ~10 minutes after round 2. Some people skipped this and went straight to HR.
HR-style questions: family background, where I'm from, why I'm planning an MS, why I didn't go to an IIT, my parents' professions, my interests, and where I see myself in 5 years.
5-7 C++ snippets over Zoom. The panel was at the FlexTrade office, and I'm a Java person, but every snippet was C++:
pointers and references
class size calculation, including padding and inheritance, even with private members
inheritance, polymorphism, overriding, overloading
Concepts: struct vs class, and the diamond problem.
HR Round (~25 min, about 10-11 days after the director's round)
It came roughly 10-11 days after my director's round, so the whole process dragged on. I got the call on Saturday, the round was on Monday at 3 PM, and I had the selection notification by 6 PM that evening, with the formal one the next day.
It's mostly a formality, a check on whether you can communicate clearly. The questions were all behavioral and fairly standard:
Introduce yourself (background, education, family)
Tell me about your freelance work, why did you leave it, and how many years of experience do you have in total
Did you go through our website, and which products interested you?
Three most important things in your life
Most interesting thing about you that's not on your resume
Strengths and areas of improvement
The work culture where you're happiest and most productive
Describe your best day at a workplace
A time you led by example
How do you decide how much time to spend on a task?
Your biggest fear, and the one thing you'd change in the world
Are you interviewing anywhere else, and do you have any offers in hand?
Do you have any questions for us? (I asked about the training process. They said there's a training phase, with a buddy assigned to you and a reporting manager.)
My advice: Prep stories, not scripts. My best answers came from real things I'd done (a LeetCode streak that inspired my friends, teaching my podcast team to run without me, why I left freelancing). Be honest about weaknesses and say what you're actively doing about them. Mine were C++ and over-planning. And be upfront when they ask about other offers.
What I Heard Others Got Asked
I didn't get these, but I overheard them or was told:
Binary search variations, House Robber, and coin change.
Technical Analyst track: a lot of Linux, puzzles, easy questions, and "how would you implement a HashMap?"
Linux: "you renamed a file and forgot the name, how do you find it?" The idea is to search by modification time. (Note for readers:
searches file contents. For files by name or time, usecode1grepwithcode1find,code1-nameorcode1-mtime, orcode1-newer. Know both.)code1ls -ltSorting: write a sorting algorithm and state all its properties.
The Plot Twist
The director's round ended around 7 PM. They said I'd get a call the next day, because there were only ~2 positions and many shortlisted candidates. They were also a bit concerned that I'm mainly a Java person, even though they knew I could answer everything.
That was a Friday. No call came, and my WhatsApp and email to HR got no reply.
On Tuesday I got the call: not selected for SDE, but I could continue for Technical Analyst. I said okay. I was honestly sad, since I'd cleared everything and still didn't get it. I mentally let go and went back to prep.
On Saturday a second HR called: a new SDE position had opened, and since I'd cleared all the rounds, they only needed the HR round.
HR round on Monday, selection notification the same evening.
What to Prepare
They care about basics, not fancy stuff. They lean toward trees and linked lists and rarely ask graphs.
DSA: bit manipulation, linked lists (write the class yourself, and practice "delete nth node from end" on a circular one too), stacks, queues, binary search, trees, and basic DP like House Robber and coin change. Practice writing these on a blank editor, not LeetCode's template.
Sorting: best, average and worst time, space, stability, in-place or not, adaptive or not, comparison-based or not.
C++ (even if you're a Java person): pointers vs references, class size and padding, inheritance sizes, virtual functions, overloading vs overriding, struct vs class, the diamond problem.
OOP: the pillars with real examples, and why OOP.
Linux basics: grep, find, pipes.
Projects: justify every choice (LLM, tokens, vector DB), not just describe it.
HR: have your story ready on why you chose this path, your 5-year plan, and your strengths and weaknesses.
The Mindset Part (Probably the Most Useful Bit)
The day before FlexTrade, I had been rejected after the first interview of another company I'd prepared really hard for. I walked into FlexTrade in a bad headspace, honestly not wanting to be there. That turned out to help me.
Since I'd just faced a rejection, I wasn't scared of another one. I was neutral about getting it or not, so I stopped asking "can I do this?" and just tried.
When they asked me to write a stack from scratch, I didn't say "I don't know, we only do LeetCode." I said "let me give it a shot." Same with the circular linked list and the rate limiter. A half-correct attempt that you talk through beats saying "I haven't practiced this."
Focus on giving your best, not on the result. You control the first, not the second.
But also: luck is real. I only got the SDE role because a new position opened up, and plenty of equally good people didn't get one. My view is that luck shows up before and after, and your skills do the work in between. If you're only lucky, you won't clear the rounds. If you're only skilled, you might still not get the seat. So build the skills, show up with a clear head, and don't tie your self-worth to one company's decision.
The one thing I'd do differently: research the company and the OA pattern. I didn't, and I'd advise you to.
Quick Tips
Practice writing full classes from scratch, not just LeetCode functions.
For design-ish questions, start with basic data structures. They'll ask for more if they want it.
If you mention something complex like threads, be ready to explain it, or drop it if they say to keep it simple.
Be patient with HR. They often can't share updates or results because of internal policies, and it's not personal. Ring them or ping them once, by mail or WhatsApp, and then let it be. Don't spam, because silence isn't a no. For me the wait was about 10 days, and it ended in a yes.
Don't give up after a "no." Mine turned into a yes a few days later.
Verdict: Selected (Associate SDE)
Overall: Positive. Friendly interviewers, fundamentals-heavy rounds, and a very disorganized timeline.
Attaching my resume here, it might be useful :) !
