FAANG Interview Tips
Dev Leader Weekly 122
TL; DR:
LeetCode, System Design, and Behavioral
... AI is likely going to change the landscape here
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FAANG Interviews Aren’t One Skill Test
If you’re preparing for interviews at FAANG or other big tech companies, one of the biggest mistakes I see people make is assuming that being “good at coding” is enough.
It isn’t. Don’t get me wrong... it’s a BIG part of it, but it’s not the only part of it.
FAANG-style interview loops are intentionally multi-dimensional. You are not being evaluated on a single axis, and success in one round does not compensate for being unprepared in another. These interviews are designed to test different skills, in different ways, across different contexts.
At a high level, you should expect three major categories of interviews:
Coding rounds: These are (generally) your LeetCode-style questions
System design rounds: These are (generally) “build me a clone of system X”
Behavioral rounds: These are (generally) “tell me about a time when...”
And the key point I want to stress is this: each one requires deliberate, targeted preparation. You should NOT wing these. Relying on general experience alone is likely only going to get you so far. And you absolutely cannot treat them as interchangeable.
Let’s walk through each one.
Coding Rounds: Yes, You Still Have to Practice
Like it or not, coding interviews at FAANG companies are still largely LeetCode-style problem solving. And if you’ve heard me talk about this stuff online, whether it’s social media posts, videos, or live streams... I am NOT a fan of LeetCode style questions for interviews. I touch on it here on Code Commute:
I strongly dislike the format because I don’t think it reflects real-world software development, and I don’t think it does a good job of measuring engineering effectiveness. I’ve felt this way for years, both as an interviewer and as an engineering manager.
That said, your opinion on LeetCode is irrelevant to the outcome of your interview. Yeah -- I’ve also had to do the LeetCode grind for principal-level engineering management roles. I don’t like it, but it’s unfortunately what’s in place. If they ask me, they are absolutely going to ask you as a software engineer.
If you are interviewing at a FAANG company today, you should assume that you will be asked LeetCode-style questions. These questions are not just about getting a solution. They are about:
Explaining your approach clearly
Identifying tradeoffs
Understanding time and space complexity
Refining a naive solution into a better one
Even very strong engineers struggle here if they haven’t practiced recently, and I feel it’s because this style of problem-solving is more “artificial”. It rewards familiarity with patterns and tricks rather than day-to-day engineering tasks -- like working in existing large scale systems.
I’d recommend that you:
Carve out time multiple times per week to practice questions. Daily is great if you can make the time for it.
Try not to look at the answers. Ideally, you’re not memorizing outcomes but instead navigating questions.
Build confidence in the “easier” questions before moving up. You’ll find the patterns/approaches can stack and layer.
So if you’re preparing for interviews, you need to carve out time specifically for this. Daily practice or several sessions per week is not excessive. This is one of those areas where reps matter. You don’t have to like it. You do have to prepare for it. You can check out resources like:
One HUGE caveat to all of this... AI is absolutely changing the world we live in as software engineers. That means interviews are very likely going to be affected. At the time of writing this, we’re starting to see some companies (including Big Tech) start to explore changes here... So I am optimistic we’ll see this move away from the current LeetCode format to something more practical.
System Design: Understanding Beats Memorization
System design interviews are often misunderstood, especially by engineers earlier in their careers.
These interviews are not about drawing the “correct” architecture. There is no single right answer. What interviewers are evaluating is how you think, how you reason about tradeoffs, and how you handle ambiguity.
A typical system design question might sound like “Design a video sharing platform” or “Design a food delivery system.” The biggest mistake candidates make is jumping straight into solutions.
Don’t do that. I know -- it’s super hard because the gears start turning RIGHT away and you’re probably excited to get into it.
The first part of a strong system design interview is clarifying requirements:
Functional requirements
Non-functional requirements
What’s in scope
What’s out of scope.
Scale assumptions
Latency expectations
Consistency tradeoffs
Only after you’ve aligned on those should you start proposing components. These are often not directly told to you by the interviewer -- you’re expected to ask about these things. These constraints will influence the system you’re about to build in the interview.
So, yes, you should practice system design. But I want to be very clear about something: memorization is a trap.
If you’ve memorized a specific “Uber design” or “YouTube design” and the interviewer asks a follow-up question you don’t understand, it becomes painfully obvious very quickly. You end up describing boxes and arrows without actually knowing why they exist. Understanding why certain components are used matters far more than remembering that they exist.
If you don’t understand something while practicing:
Stop and dig in! This is the perfect time for it!
Ask an LLM. Ask for pros and cons. Ask why one approach is preferred over another.
Build intuition, not scripts. What should happen to your design if one of the constraints changes?
Check out newsletters from awesome creators like System Design Classroom and The System Design Newsletter
As you move up in seniority, system design tends to carry more weight. Junior roles skew more heavily toward coding. Senior roles shift toward design, tradeoffs, and technical leadership. Every company will do this a little bit differently, but that’s a generalization that should be applicable.
Which brings us to the last category.
Behavioral Interviews Are Not About Technology
Behavioral interviews are where a lot of otherwise strong candidates stumble.
These questions are not asking you to explain your tech stack. They are not asking you to justify architectural decisions. They are asking you to demonstrate how you operate as a human being in a team. Questions like:
“Tell me about a time you disagreed with a teammate.”
“Tell me about a time you handled conflict.”
“Tell me about a time you had to make a decision with limited information.”
Even when the scenario is technical, the evaluation is not. This is the important thing to keep in mind, because it’s very easy for us as engineers to want to explain all of the interesting technical details -- it’s just not the right time for it.
Interviewers are listening for things like:
How you communicate
How you handle disagreement
Whether you listen to others
How you navigate tradeoffs
Whether you can reflect on outcomes honestly
The STAR method (Situation, Task, Action, Result) exists for a reason. It forces structure and clarity. If you struggle to frame answers, this is an area where using AI to rehearse and refine your stories can be incredibly effective.
One important tip here: many companies publish their core values. Those values directly influence behavioral interview questions.
If a company values “bias for action,” expect questions about acting under uncertainty. If they value “ownership,” expect questions about accountability and responsibility. If they value “collaboration,” expect questions about conflict and alignment.
Not only can you find these core values on company websites, you can work with your favorite LLM to help you out with these questions. For example, if you are practicing for your Meta interview, you could ask:
I am applying for a level XYZ software engineering role at Meta. Factoring in Meta’s core values (optionally give it the link to assist with accuracy), give 10 level-appropriate example behavioral interview questions.
(You can even steer the prompt to be more specific, so things like conflict resolution, project management, handling ambiguity, etc...)
You can and should practice behavioral interviews intentionally. This is not fluff. These rounds carry real weight, especially at senior levels.
AI Is Changing Interviews
I wanted to put this explicit reminder in here again that AI is already forcing changes in how interviews are run, especially coding interviews. LLMs can trivially solve many LeetCode problems. That reality isn’t going away, and I’m sure we’ll see more and more of this surfacing.
Some companies are experimenting with allowing AI during interviews. Others are shifting toward collaborative exercises. Others haven’t changed at all yet. But there IS change happening in the industry.
The important takeaway is this: you should prepare for the current reality, not the future you hope for. And as you are preparing for the current reality, keep tabs on how these processes are changing -- because change is happening rapidly.
Today, FAANG interviews still test coding, system design, and behavioral skills independently. Until that changes across the board, you need to be ready for all three. I’ll do my best to report on what I see changing as I see it changing because this is a critical part of getting your foot in the door to do awesome engineering work.
The Big Picture
FAANG interviews are not a test of how smart you are. They are a test of how prepared you are across multiple dimensions.
You need:
Focused practice for coding rounds
Structured thinking for system design
Self-awareness and communication for behavioral interviews
None of these are optional. None of them are interchangeable. Your level and which company you are applying to may dictate the weight of each of these categories... but you need them all.
If you approach interview prep intentionally, with respect for each category, your odds improve dramatically. If you assume one strength will carry you through the entire loop, you’re taking a risky bet.
Prepare accordingly. Feel free to send in any questions so that I can help answer!
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As always, thanks so much for your support! I hope you enjoyed this issue, and I’ll see you next week.
Nick “Dev Leader” Cosentino
social@devleader.ca
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