Get a job, Whiteboard Coding Interviews: 6 Steps to Solve Any Problem (1)

Whiteboard Coding Interviews: 6 Steps to Solve Any Problem (1)

So one thing I wanna talk about today is how to ace that technical interview.

And this is really one of the hazing processes of getting a job in tech is to you gotta get into a room with another developer, someone you've just met, they're gonna introduce you, introduce themselves to you and they're gonna give you a problem and you're gonna have to solve it on a whiteboard which is totally unnatural, I get it.

Usually you don't code on a whiteboard.

Usually you're working with people you know.

So it's a pretty intimidating process for entry-level developers, actually to be honest it's intimidating for everyone.

It's one of those things where even to this day when I'm interviewing for technical jobs I still get nervous about it, even though I've done hundreds of them, I've been on both sides of the table and I've also,

I've practiced a lot of coding problems throughout my lifetime, it still makes me nervous.

So that's very natural.

I wouldn't be upset that you're nervous about it,

it's just something to practice for.

So at Fullstack we've invented a method that we like to call the REACTO approach to solving interview questions.

So it's R-E-A-C-T-O, nothing to do with the REACT framework

it's just something that as I was coming up with an acronym

I wrote 'em out kind of the exact steps

and REACTO was the acronym that came out.

So what does REACTO stand for?

Repeat, give examples, describe your approach, implement the code, test the code, and then talk about optimization.

All right so let's start with R, repeat the question.

You wouldn't believe how many times I'm in the interview room with a candidate...

and I'm excited for the candidate...

and we're having a good chat...

...and then we get to the programming question...

and I say implement this thing...

and the first thing they do is they take the cap off the pen and they start writing on the whiteboard before they even really understood the question

And I can tell because the first step they say is something

and I just know they're gonna go down the wrong path.

Now one secret is that when you're interviewing with somebody - people like to use the questions they're comfortable with

So very likely they've done this question 100 times

And this is the first time they're seeing it.

So they already know all the paths that you can go down that are gonna be incorrect.

So you're going down the wrong path immediately and that immediately puts the whole interview onto a tough foot.

So the first thing you should do is really just repeat the question and that will oftentimes help A, help you understand it better and B, really make sure that the things that you don't understand you can work out with the interviewer as you're going through the repeating of the question.

The second thing is to start writing out various examples.

So before you even write out any code, write out hey here are the parameters that I'm gonna pass into my function and what did I expect to get out, right?

So just create a little table, a two-column table and say given these parameters what output do you expect, right?

This is another way to really understand what exactly the question is asking, because you oftentimes will get a lot of understanding by just understanding input, output, input, output, right?

You're trying to, one way to think about this is that this problem is a black box.

How can you start understanding what's inside the black box before you know giving something into the black box, what comes out on the other side?

So list out examples.

This is another great way to keep the conversation flowing and make sure that you understand what the question is asking.

Now the third step A, describe your approaches right?

So start talking about the approaches you're gonna take.

Are you gonna look for a recursive solution, an iterative solution, a heuristic solution?

So give the interviewer some insight into your logic and thought process and really help them understand kind of the track that you're going down so that you know you also get a little bit of read on if you're on the right path

but how they respond to your questions.

So if you say you know what?

I'm gonna take a recursive approach

and they look at you like excuse me?

Then you know that you're probably on the wrong path right?

So if you say well I'm gonna take a recursive approach,

I'm like okay, that makes sense,

then you're playing the interviewer a little bit

as well as playing the question.

So take some time to talk about your approach.

Again, oftentimes people give advice keep talking,

keep talking at your interviews

and what they really mean is this kinda stuff, right?

Keep talking about your thinking

not what's going on in the code

and you realize there's three things that you've done.

You've probably spent about five minutes

and you haven't taken the marker out of the case

and started writing on the board.

All right, so after you've talked about your approaches

and you've confirmed an approach,

you say this is what I'm gonna take,

usually the interviewer will give you some sense that you're on the right path.

Then you start writing on the code, going down the path of writing code.

So C in REACTO is for code and you know there's so many things I can say about code,

we can dive into those further if you have questions

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