Now ongoing: JS challenge Winter 2015: Mail Filtering Engine

Liked our past challenges? Take part in the latest one!

Hola’s Spring 2015 JS Competition: winners!

Thanks to all participants! See all solutions and result rankings in the GitHub repo.

Welcome to Hola’s Spring JS Competition!

There are very few really great programmers, and we'd like to give them a chance to prove it to the world, and get a nice prize in return!

The challenge: generalize NodeJS's linklist

NodeJS has a very high performance, low-memory overhead implementation of a linked list:

This implementation is specific (idle items only), and does not allow list parent to hold two or more different lists in the parent list object.

Your challenge is to make it generic, while not reducing performance, and include tests to show that performance hasn’t been degraded.

The fastest, most efficient, most generic implementation wins the prize!



Why are we doing this

If you are a truly great programmer, we’d like to know you, and to get a chance to tell you more about us. If interested, we'll invite you for an interview.

More about Hola!

Hola was founded by serial entrepreneurs with the goal of making a better Internet. Hola’s overlay P2P network for HTTP has disrupted the consumer VPN and Online Business Intelligence markets, and is on its way to disrupting the $5B/yr CDN market. Hola is well funded and profitable (more at

Previous challenge (Ended June 22, 2014): make strftime 50x faster

Make strftime 50x faster than original JS (and 25% faster than GNU libc strftime)

Thanks to all participants! See all solutions and benchmarks in the GitHub repo.

We use nicknames instead of real names to protect privacy of participants. If you explicitly do want your name, email etc. to appear in the results then please contact us.