Beautiful JavaScript Winner Code Walkthrough

boomx's Beautiful JavaScript Solution

“It’s rewarding. It feels good to come up with a solution, and just to in general practice how you approach solving problems.”

– Beautiful JavaScript winner boomx on CodeSignal

The CodeSignal Beautiful JavaScript contest wrapped up a few weeks ago, and the winners were CodeFighters boomx, arnav_a2, and marcusekeenan. Each of them won a trip to San Francisco and three nights at a hotel downtown. We recently had the first of our winners visit us!

boomx is a software developer in North Carolina. Earlier this year, he went to a conference where a presenter talked about how important it is for programmers to stay sharp by practicing outside of work. One of boomx’s coworkers mentioned that CodeSignal is his favorite site for practicing programming, so he signed up to try it too. boomx solved a few challenges here and there, but really got into the site once he saw the Beautiful JavaScript challenge. Now he tries to solve the daily Challenge as often as he can to keep his skills sharp!

We had a great time hosting him at CodeSignal HQ. Our Engineering team really enjoyed getting to talk with him about his solution, coding in general, and of course JavaScript!

Beautiful JavaScript Winner boomx
Oh, you know, just casually pointing at a contest winner.

During his visit, he was kind enough to give us a great walkthrough of his solution. He started by talking about his original naive solution, and then about how he optimized it. It’s really interesting to see the code’s evolution from its (still great!) beginnings to the expressive, readable, and concise solution that you can see at solution #191. Watch his explanation below!

Thanks, boomx!

We’ll post the next two solutions when our other winners visit us later this year, so stay tuned!

April Marathon Recap

april coding competition marathon

As you may have heard (from us, because we won’t stop talking about it), CodeSignal hosts a monthly coding competition that we call the Marathon. CodeSignal Marathons, unlike their IRL counterparts, only last for one hour. And while you may not get a medal and a free banana afterwards, the top ten participants do get $50 Amazon gift cards, not to mention coins and XP! Our content engineers create brand new challenges for each Marathon, all tricky, fun, and guaranteed to get your brain in gear.

We had a great turnout this month. Over 800 people registered! But of course, there could only be 10 top coders… and only one winner.

[table id=12 /]

Congrats to our top ten competitors, and a big high five to CodeFighter Alex_2008 for coming out on top!

CodeSignal CEO and founder Tigran Sloyan and Content Engineer Damien Martin (author of our awesome new CodeSignal Solves It and CodeSignal Explainer series) provided live commentary during the competition. If you missed the tournament or the live broadcast, we’ve got you covered. You can take a look at the questions from the Marathon and watch a video of the commentary at the same time!

Thank you to everyone who participated and/or watched the live broadcast!

The May Marathon will be here before we know it, so mark May 27 off on your calendar! We’ll post the registration link soon.

The monthly Marathon is a great way to get in some solid coding during the weekend. We love seeing repeat competitors getting better each month they participate in a Marathon. Practice makes perfect! Whether you’re preparing for technical interviews or just becoming the best coder you can be, competition is a great way to hone your skills.

Previously on CodeFight On!

March Marathon Recap

Tell us…

Did you watch the April Marathon? Did you participate? Either way, let us know what went well and what we can do better!

April Marathon and Live Broadcast

CodeFights coding tournament marathon

You might not know that every month we run a huge coding tournament. We call them Marathons, but unlike a running marathon, they only last one hour. (And your legs won’t hurt tomorrow!) Each Marathon consists of 10 questions that have been specially created by our team of Content Engineers. They’re fun, they’re tricky, and they’ll get your brain in gear! And if you’ve never participated in a competitive coding event before, this is the perfect introduction.


If you want to compete in the Marathon, sign up on CodeSignal. As of this second, 730 people have signed up, but thanks to the magic of the internet we’ve got enough room for everyone who wants to join us. You can register even after the Marathon starts, but don’t wait too long!


Even if you don’t want to participate in the Marathon, we’ve got a great way for you to join us. CodeSignal CEO Tigran Sloyan and Content Engineer Damien Martin will be broadcasting live and providing commentary the whole time! Watching other people code, and getting play-by-play explanations of how the coders are solving the challenges, isn’t just fun. It’s also a great way to learn about coding and level up your own skills and understanding! To watch the live commentary, head over to our Facebook page.

Join us for this coding Marathon!

So whether you’re participating in the April Marathon tomorrow or just want to watch the action as it unfolds, we’ve got lots of coding goodness for you tomorrow! Both the Marathon and the live broadcast start tomorrow, April 29, at 10AM PDT.

Previously on CodeFight On!

March Marathon Recap