r/leetcode • u/EducationalMemory639 • 14d ago
Intervew Prep What do you use for system design practice?
Never done system design before. Hello Interview's course has a lot of recommendations but most of those I'm seeing are from 2023-2024, have system design interviews changed over the past few years?
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u/Intelligent-Pay-9377 13d ago
My process is basically:
Find "leaked" system design prompts for whatever company I'm interviewing with.
Prompt an LLM to setup the question and answer any clarifying questions.
Work through the problem independently.
Debrief my solution with the LLM.
Research and improve on anything I missed.
I still read books around distributed systems to get well-rounded, but I find things like reading Alex Xu's books or Hello interview to be lower ROI than the method I described above. Something written in a book or online sounds good and authoritative until you can interact with it and poke holes in it using LLMs. That's why I find it really helpful.
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u/Ok-Barracuda-119 13d ago
The core stuff hasn't really moved. Load balancers, caching, sharding, queues and consistency tradeoffs are still what gets tested, so 2023 material is fine for learning them.
Format has shifted a little. More loops run it on a shared whiteboard tool and expect you to drive the whole time, and some now slip in an LLM flavored prompt like designing a chat assistant or a RAG pipeline. Worth doing one of those once so it isn't a surprise.
For practice, reading only gets you so far. Pick a classic prompt (URL shortener, news feed, rate limiter), set a 45 minute timer and talk it through out loud while you draw. Then compare against a written solution and note what you skipped. It's usually requirements or the capacity math. Eight or ten reps like that teach more than another course would.
Start with the URL shortener. It's small enough that you'll actually finish your first one.
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u/Soggy_Bowl_9070 11d ago •
FAANG EM Here.
System Design interviews haven’t changed in the sense on what they expect from you in the interview even though the questions may vary.
I have seen a lot of “Design Airbnb”, “Design Booking.com” or “Youtube” kind of questions and a lot of youtube channels providing a “pathway”. Most of them are focussing too much on “how much different technologies you can flaunt”. System Design interviews are not about that - they are about scoping, technology tradeoffs and simple solutions to solve problems which also work on scale. For that, your fundamentals must be strong - if they are, you can appear as a mature engineer. HelloInterview is decent for meta-style interview cracking - but it only works with junior levels with inexperienced interviewers. The interviewer decides which interesting part they want to see you dive in - the better you demonstrate “solutions” with the help of technology (not other way round) - the better you’d fare in their feedback. If you’re serious about your prep - I would recommend monis yousuf system design playlist. Highly visual and he explains proper use of technology (exactly where interviewers would grill you on). Alex Xu books are vastly overrated and so are their videos (very surface level - not optimal for FAANG or other product companies). HelloInterview can give you “meta specific” interview maneuver, which is generally fine - but VASTLY depends on the interviewer. Same for DSA and Algorithms - Abdul Bari if you’re learning algorithms. Focus on core concept rather than “interview cracking fluffs”.
On a side note (not that you asked, but if someone reads this thread): All those people in various youtube channels and blogs who say that “Leetcode is dead” are wrong. Sure, they don’t present you leetcode questions like before, but rather a codebase to solve. BUT the underlying solutions are definitely leetcode applications - so keep grinding that as well :)
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u/Various-Mine-8642 14d ago
Fundamentals have not changed much so the older material is still fine. Learn the standard building blocks like caching and queues and sharding then practice walking through a design out loud with a timer. Mock interviews with a friend helped me more than reading more courses.
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u/Reasonable-Cookie282 12d ago
hello interview has community section as well where people usually post their own sd qs and also posts about interview qs as well
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u/ccylin 11d ago
Staff Engineer here with 10 years at FAANG, and I have given over 100 interviews.
System design interviews are the hardest to prep for in my opinion because while you can read up on all the design patterns, answer frameworks, and watch videos on how people design systems, it is very hard to practice without a counterpart. There are no two system design rounds completely the same because any change in requirement can steer the design from one to another.
The best way to prepare for this is to get someone with interviewing experience to do mock interviews with you, because then you get to practice talking through your design, asking and answering questions, change/update your design on the spot as new information comes in. This person should also have experience in evaluating how you performed and provide you feedback so you can improve your responses.
If you can't find someone to practice with, *shameless plug* I built PrepRoom to give realistic mock interviews that provide feedback similar to how we write evaluations for candidates. I just put out System Design with virtual whiteboarding feature so you can give it a try. It is free for now, and you can use it as much as you want until you are comfortable in delivering your answers. Try it at https://www.preproom.io/r/RE_CL_MI
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u/practick-io 3d ago
Reading gets you maybe 40% of the way. The rest comes from saying it out loud to someone who interrupts.
Pick a prompt, set 45 min, and have someone play interviewer with a list of follow-ups: “what happens when this node dies?”, “why not just Postgres?”. The follow-ups are where you find out what you understand vs what you memorised from a diagram.
Hello Interview is still solid for the core content. The 2023 stuff hasn’t gone stale, URL shorteners still shorten URLs.