How To Be a Better Developer with Programming Challenges

TopCoder

TopCoder was the one of the first (if not the first) service to offer coding challenges.

Whereas similar services offer explicit recruitment services to customers, or don’t have a business model at all, Topcoder has a few models that are probably unique in this area.

You, as a developer, can solve challenges, but can also participate in events that are somewhere between a paid gig and a contest. In fact, companies can create an event if they need fresh ideas for development projects, such as:

• UI/UX design
• Application development
• Algorithms

Candidates compete to win a payment from the company. As you might expect, there’s a lot of competition, and usually only one winner per project. On the bright side, it’s absolutely an excellent way to test your capabilities on a real, tangible project.

The list of companies you might potentially work for are respectable names, such as:

• NASA
• IBM
• eBay
• Honeywell

There are also recurring tournaments, single-round matches and other contests, some of which allow or require teams. If you opt for a team contest, you collaborate with others in a hackathon-like format to solve a problem.

There’s a lot more to TopCoder than can reasonably be discussed here — covering it all would monopolize this article. Have a look, explore, then feel free to talk about what you find in our forums!

CodinGame

CodinGame is about coding games, but it’s not a freeform blank sheet of paper where you have to invent and draw your game.

Don’t let the presence of the word “Game” fool you into thinking this is a casual site — it’s not. It is, however, a unique way to stimulate your brain. In coding game you’re given:

• A game plot
• A scenario
• Some actors
• A goal

Your task is to write the AI. Pretty awesome and interesting, eh?

The site provides all the graphics, animations, effects, scenography, etc. CodinGame is a bit like being on a movie set where you’re the director; you write your script to control your actors, and then you watch them execute that script.

The list of languages is pretty long — 25 in total. For you Apple Developers, there’s Objective-C and Swift.

How does it work? You have a browser-based IDE, and it’s a full featured build that includes a:

• Code editor
• Console output
• Help panel that has a description of the problem to solve
• List of test cases
• Action area, with buttons to run tests, start the simulator, submit your solution, etc.

The editor comes prepopulated with some skeleton code and a clear indication of where to write yours. Once you’re done coding you start running test cases.

When running a test case, the simulator actually shows the game with the AI-controlled actor following the orders you gave with your code. By the end of the simulation you know whether the test passed or not. If not, most likely your actor was killed. :]

CodinGame provides you with a rare opportunity to watch your code come to life — and it’s as amusing as it is stimulating. If you like games and coding, then this is the place to be.

Following an established pattern for coding challenge platforms, CodinGame also offers services that are designed for companies that want to hire candidates.

Now tell me: when you’re looking for your next job, which of the following two would you choose to show your expertise?

1. An option to write code to implement a linked list on a “cold” white board
2. An option to write AI for a bot whose goal is to kill its enemies that lets you use your browser for your IDE

The choice is clear. Killer AI bots are always the better choice for showing off your skills. :]

CodeFights

As soon as you land to the CodeFights, you immediately notice the appealing superhero avatars. Disappointingly, you can’t use them for your own profile — they’re just there for looks.

However, the site is not about cool avatars; it’s about coding and debugging.

Once you’ve registered, you’ll get an invite to a 1:1 fight with a bot. It’s pretty easy — any developer with 1 day of experience should be able to win the fight.

Each challenge consists of a three-round fight, and there are three types of challenges you need to solve:

• Debug: you’re given some code and must locate and fix the bug
• Recovery: you’ve given some incomplete code and must fill the missing part
• Code writing: you implement a function from scratch

Each round comes with a description of the problem to solve.

One downside of this otherwise useful service is the restricted list of languages. There’s also no Swift or Objective-C, so iOS and macOS developers may feel some disappointment.

On the upside, you have its browser-based editor that sports autocompletion and smart navigation — you can use CTRL + left or right arrow to move to the previous/next word, even with camel case identifiers.

Besides battling bots, what else can you do on CodeFights?

• Fight against real people — either friends you invite or random opponents
• Join marathons
• Participate in tournaments
• Challenge company bots (Dropbox, Uber, Asana, Quora, and more), which can help you get noticed and maybe even hired
• Create and submit your own challenge

CodeEval

CodeEval seems like a front end for a recruitment business. While that’s not entirely a negative thing, it is the feeling I got after registering and accessing to the dashboard. But that’s just my subjective take.

Once in the dashboard, I spent some time wondering what to do next. Unlike the other services reviewed here, there’s no guidance and no “check this” nor “do that” kind of UI. You have to explore on your own.

The number of available languages is 26. You won’t find Swift, but Objective-C made the cut. Besides the dashboard, which looks very nice, the rest of the experience is a little spartan.

The editor is suitable. It has auto-complete, but the comment font color is a little difficult to read. Copying and pasting into an external editor is highly recommended.

At CodeEval, there is only one type of challenge: you versus yourself. There are three lists of challenges that are divided by difficulty.

Another potentially useful section is the “Jobs & Offers” page. Here you can find job offers, some of which require you to solve a problem in order to apply — most likely, it’ll require coding. The rest of the posts are more traditional, static job ads.