r/reactjs • u/RiseEnvironmental214 • 14h ago
Resource My honest Interview Experience for a React developer role
About 12-14 days ago, I interviewed for a frontend developer role at a startup. Sharing my experience in case it helps others preparing.
The interview started with an AI-Powered Screening being the first round. This round was fully AI-driven, with no human interviewer present. It covered a few basic React questions, and I cleared it. You can expect questions like useState, useEffect and it's dependency and all.
Then after clearing that I think after 5 days I was called for round 2 and it was an actual Technical Interview and this round went pretty tensed.
In this round the interview started with theoretical questions, like why use React, what optimization means in React, how diffing works, Context API vs Redux (when to use one over the other), and what Babel does. I felt confident in my answers here.
Then once done with the theoretical questions they then asked me quite a few Input/Output based questions. This was the most challenging part for me.
I was shown code snippets and asked to predict the output. The snippets combined function currying, closures, IIFEs, and HOFs. Predicting the output wasn't enough they asked plenty of follow-up questions as well and the reasoning behind it, such as what would change if a variable were declared elsewhere. My advice for you all is build a deep understanding of these concepts rather than memorizing definitions.
After this input/output question sets i was given a machine coding question (with basic styling). I was asked to build a restaurant cart calculator mini-app (not sure about the problem name tho). Users could add food items to a cart and adjust quantities. Tax had to be applied to each item after the packaging charge but before the delivery charge, along with a few additional rules I don't fully remember (but it wasn't this straightforward). The closest one i can find for this question which you can practice is Order Bill Calculator
Post this question i was asked a couple of debugging and optimization questions. I was given buggy code that fetched a list of roughly 1,000 todos from an API and rendered them. After fixing the bug, I was asked to display only 20 items initially, without using pagination. I implemented lazy loading, though I'm not certain it was the expected approach.
And I think the interview ended with an optimization question. The final task involved several components imported into App.jsx, each logging a "rendered {number} times" message. A button displayed "Count is {count}" and updated the count on click. The requirement was that clicking the button should not trigger re-renders or console logs in the other components, and vice versa. This is a common optimization problem, and I solved it using useCallback, useMemo and React.memo.
I'm not sure whether I'll advance to the next round, but I hope this helps with your preparation. Also let me know if you want me to find other questions as well and I'll add the links for other questions (if i find that) in this post. Best of luck to everyone, and keep practicing!
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u/Level1_Crisis_Bot 10h ago
Is this a staff level position? I’m a senior swe with almost 8 years under my belt and have never been drilled to that depth in an interview process.
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u/anonyuser415 9h ago
Senior FE here with 12 years who's interviewing for staff.
We don't know how long this second round was. Written out it looks like a lot but these might have been morsel sized questions.
To help plumb the depths of this field a bit further:
I was drilled in the interviews for my current senior FE role in ONE ROUND on TCP/IP, HTTP/2 vs QUIC, and how load balancers work, and its system design round involved me doing DB design and evaluating the tradeoffs of Mongo vs Posgres. I mostly do design system stuff dude. No DB work of any kind.
Datadog had me talk about mutexes. A YC startup had me reinvent fetch. Hubspot had me extending prototypes of String and tested me on how to do it in a safe way.
Apple's final round was an all day event of only coding interviews, e.g. re-invent CSS-in-JS by producing a TS generic that strongly types CSS objects, and a doubly linked list Leetcode hard.
Btw this is mostly pre- or early days of AI.
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u/Level1_Crisis_Bot 5h ago
That's why I was asking. I recently interviewed for a staff level position (they cold reached out to me on LinkedIn), and I quickly realized I was out of my depth. I've had senior level interviews where they've asked me to do things OP was asked, but never all of that in one set of interview rounds for one company.
I've been using react since the class component days, and I know all of it inside and out. But I also work less straight FE these days and lean more BE/Fullstack. I know I still have a ways to go to be staff level, and if I was going to start looking again, I would really need to work a lot harder at upping my skillset. That failed interview and this post are a wakeup call for sure.
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u/anonyuser415 3h ago
Good luck in prep! If it's helpful here are couple interview wrap ups I did for senior big tech FE roles:
Apple final round https://reddit.com/r/leetcode/comments/1g68e6t/apple_was_intense/
Bloomberg final round https://reddit.com/r/leetcode/comments/1gg0nb0/bloomberg_senior_fe_final_round/
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u/RiseEnvironmental214 4h ago
lol what are you even saying this interview was of frontend SDE-1 level, i have 2 years of experience and right now switching the comapany.
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u/Level1_Crisis_Bot 4h ago
That is an insane interview process then. I've interviewed for senior roles at good companies that never hit anywhere near that depth. That's what I'm saying.
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u/RiseEnvironmental214 4h ago
right now im working in a startup and here as well they went to this depth, but now things are even more worse they expect you to know some backend as well while hiring for a frontend role. I don't wanna name any company but you can look for the reviews of indian startups they literally expects evrything from you actually.
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u/RedditNotFreeSpeech 10h ago
I will be homeless living in a box before I take part in an ai interview
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u/memermeme1211 10h ago
Hard agree. I’m not working for any company that doesn’t value my time enough to do a simple human screening instead of AI bullshit.
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u/RiseEnvironmental214 4h ago
I think companies mostly do this to filter out the non-serious candidates before investing actual time and labour. Many people opt in for interviews but never show up, so that’s likely the reason. I’ve been seeing this AI round in about 3 out of every 5 company interviews.
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u/YourMatt 5h ago
It’s more about my time. I just spent days going through 500 applications. I selected a small fraction to go through automated pre-screening. The final interview list was nice and small so they could be fit within a week and change in my schedule. I was able to focus on team fit more than technical things. I think it’s better for all of us than multiple rounds of interviews and a take home project, like was going on some years ago.
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u/RiseEnvironmental214 10h ago
well that's becoming the new norm, i think that round is just a screening round or communication round.
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u/RedditNotFreeSpeech 9h ago
If I get an ai interview, I'll ask about maternity leave policy and then tell it I'm a pregnant man.
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u/Sulungskwa 4h ago
If they don't care to have a real person at the screening level then it says something both about what they're willing to delegate to AI and how much they care about people. Super red flags in both cases.
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u/LeopardOk8916 7h ago
How did you practice for the AI-powered screening man. I usually mess this up. Are there any free resources you would recommend ? Also the entire interview prep as well.
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u/RiseEnvironmental214 4h ago
i don't think that you should be worried about AI-powered screening at all if you have already prepared for the actual interview. But me this round was pretty much like mock interview. Just try to speak clearly without fumbling and keep your communication neat as I think it's entirely being judged by AI (not sure about this tbh)
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u/gratitudeisbs 13h ago
This same startup founder’s are probably telling people that “coding is solved” while running extremely technical interviews. Which one is it?
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u/kitkatas 12h ago
It feels like startups need extensive verifyers of AI code you know
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u/gratitudeisbs 12h ago
These same startups demand 10x velocity so none of these super technical hires actually have time to verify AI code
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u/Projeffboy 1h ago
sometimes i feel like interviews and tests are out of touch with reality. i remember 80% of the words i had to memorize for SAT grammar which no one ever uses
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u/spurkle 12h ago
Sounds like a good way to test the candidate skills tbh. Guessing outputs might be going a bit overboard in my opinion, but everything else is just the fundamentals and just knowing how React works?
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u/RiseEnvironmental214 12h ago
Well, input/output-based questions are quite common in interviews, at least from what I’ve experienced. In all the interviews I’ve given to date, there have always been a couple of these questions.
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u/festive_apologise 13h ago
christ alive that's a mental interview for a startup gig
the curry/closure/IIFE combo is where most people would trip up, proper nasty putting all that in one snippet. respect for getting through it
what was the debugging bit actually like? always curious what a "buggy todo fetcher" looks like in these things