How to NOT Fail a Technical Interview transcript

the single worst moment of my life was the moment i was born i wish that were true but as a software engineer i've experienced far worse things during technical interviews if you're lucky enough to survive tutorial hell before the age of 25 and find a way to impress the algorithms that automatically read your resume you get dropped into a high-stakes life or death game with a six-figure salary on one side and orbeez on the other you can tell yourself the interview process is broken and maybe it is but like most things in life you can't control it and just have to play the game in today's video you will experience the psychological rollercoaster ride that is the technical interview along the way you'll learn the secrets to high pressure problem solving on the spot and how to impress the interviewer even if you totally suck at writing code to make this hyper-realistic i've invited a special guest who's conducted hundreds of interviews in the real world let the story begin it's been a long difficult year of hashtag learn to code i've turned down dates with beautiful women stopped doing flat earth research and even cancelled netflix all for the opportunity to stare at a computer screen for the rest of my life thanks to this awesome video i watched on youtube i finally landed an interview with big scary tech corporation i've got dozens of leak code questions and a bunch of half finished udemy courses under my belt nothing can stand in my way now i'm about to jump on this call and change my life forever hello mr fireship my name is the primes in welcome to hell welcome to hell i'm just kidding i'll be conducting your interview today you know let's just get straight into it i'm going to ask you actually a classic question it's called fizzbuzz i want you to print out numbers 1 through 100 but if it's divisible by 3 i want you to print out fizz if a number is divisible by 5 please print out buzz but if it's divisible by both 3 and 5 please print out fizz and buzz fizzbuzz how cliche is that i mean i just built my own compiler in javascript last night this is too easy wait a minute i have no idea what i'm doing here hash map link list mom mom why am i so dumb wait directed graph i i can't do it i'm just going to tell them i can't do it binary tree i'm an imposter i'm blacking out a few moments later uh mr fireship before we write any code uh let's just talk about the problem how would you kind of approach a problem like this you know what i think i've already failed this interview which means i don't care anymore and magically when i stop caring the anxiety goes away screw the code let's just talk about the problem okay so it looks like we have three conditions here and when we have conditions we use a conditional statement like if one way i could represent this is with a flowchart on a whiteboard or if that's not an option i might start by writing some pseudocode because i don't want to worry about syntax or boilerplate before i even know what i'm going to implement for each iteration of a loop we have a number if it's divisible by 3 and 5 we print fizzbuzz otherwise if it's divisible by 3 we print fizz or if it's divisible by 5 we print buzz and finally just print the number if none of these are true wow so this is actually a very simple problem when we take the time to break it down i was totally overthinking it i was expecting something with a really complex solution because this is big scary tech corporation after all you know i can't give you the answers but i do really want to see you succeed so feel free to ask questions as we go along that solution looks pretty good so how would you take that and turn it into code i'm most comfortable in javascript so i'll go ahead and use that for the implementation first we'll need a loop that iterates 100 times as i'm writing this code i'm not thinking about getting things done quickly but rather i'm taking my time and making sure i fully understand the requirements before wasting my time writing a bunch of code that i'll have to correct later what's really important is that i think out loud and explain my decisions throughout the process normally i like to use four each for loops but in this case i'm going to use a traditional for loop and not four each because i happen to know that four will result in better performance now even if what i'm saying isn't totally correct it's important for the interviewer to understand my problem-solving process saying something is almost always better than saying nothing at all unless of course you say some dumb ass in which case it may be optimal to just shut the up before you set foot into the thunderdome you should practice literally saying everything out loud as you solve a problem personally i hate talking while i write code and it just takes a lot of practice to get comfortable with this follow the abc rule i just made up which doesn't mean always be coding but always be chatting another tip is that if you get confused and freeze up don't just sit there but try to come up with a question the longer you sit there and stare at the headlights the more likely you are to lose your composure can't have anyone freak out out there okay we've gotta keep our composure we've gone too far there's too much to lose composure i'm a little confused here so i might ask a question like should the program take an input and return an answer for a specific index or should it always iterate over all 100 answers good question a loop is just fine now i feel like i'm going in the right direction so what i'll do next is create a few conditional statements that line up to what i sketched out on the whiteboard now the tricky thing about fizzbuzz is determining if one number is a multiple of another number i guess i could divide by the target number and if it's an integer it's a match but if it's a decimal then it's not a match that should work so when it's 3 will log fizz when it's 5 will lock buzz but if it's false on both of these then we'll just console log the number yeah i think that looks good let's go ahead and use bun to run it just to show off my knowledge of blazingly fast javascript tooling and yes it works perfectly i'm a goddamn genius interesting what can you do without magical type conversion do you know what modulo is ah man he's not impressed at all i'm such a loser modulo i've never even heard that word in my life oh wait are you talking about the remainder operator in javascript yeah you do have the modulo operator correct why don't you give it a try yeah that would make more sense here what it does is give us the remainder when doing division so if that number is 0 then we know that it's a multiple of whatever number we're trying to divide by that gives us a solution that isn't so dependent on the loosely type nature of javascript it's usually a good idea to avoid language specific magic the interviewer might be a c developer with 50 years of experience who's going to think your clever little javascript tricks are mid af the modulo operator is available in basically every language so it's best to stick with that this is looking pretty good but can you make fizzbuzz print on a single line oh yeah that's kind of not correct is it okay i think i have an idea but i remember reading this article that's messing with my head right now that said the else keyword is an anti-pattern maybe i should stop believing everything i read on the internet let's give it a try and talk through it we'll first check for the fizz buzz condition then use if else a couple times to check for fizz and buzz and then finally we'll use else to log the number itself not only does this put fizz buzz on a single line but the code is just more simple now in fact i don't think it can get any better oh that looks correct now what happened if i wanted to add some more conditions let's say 7 is bass how are you going to deal with that ah man i knew it else statements really are garbage always believe everything you read on the internet it's never failed me when you have a lot of conditions to check one thing you generally want to do is try to extract the data out of that statement we can easily do that here by defining a variable for the thing we want to print now we could set up a switch statement to check all the different conditions but i think using if is just as good if not better as you can see here i have github copilot enabled but let's just keep that on the download because i really need this job now instead of console logging here we'll just mutate the variable this allows us to eliminate the fizz buzz check and can also scale better if we decide to add additional words to it impressive very nice impressively very nice blazingly correct now how would you describe the performance of your algorithm i would describe it as strong to quite strong as you can see when i run it there's almost no lag time because my holistic approach is so blazingly fast well that's one way to describe it i was more talking about big o time complexity oh yeah i guess i should have studied big o a little better before doing this interview if the fizzbuzz game were to go on forever i'd say we have linear time complexity or o of n however technically the game is only played for 100 steps which would simplify down to 01 or constant time wow i can't believe it's been an hour already i blacked out where the hell am i is this heaven oh hey congratulations you've got the job here's your offer sheet with a 400 000 salary and the job is fully remote with unlimited vacation time your first task you'll be working on is changing all of the blue buttons to a slightly different color blue wow i can't believe it i've spent the last two years pouring my blood sweat and tears into this and my mom is going to be so proud hold on just one second [Music] uh it looks like we've just implemented a hiring freeze um i'm gonna have to rescind that offer congratulations now you know how to bomb your technical interview just like me make sure to subscribe to the primogen for more awesome developer content thanks for watching and i will see you in the next one