Upcoming coding events

Upstream Festival
23 May, 2023 14:00-17:30

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Upstream Festival Coding Challenges

Join on the 23rd of May for 2 major challenges!

Where: Poppodium Annabel, Rotterdam
When: 23 May 14:00-17:30
Languages supported: C#, PHP, #GO

Past events

This was a multi-language coding challenge

We had a great, friendly event on 15-03-2023, 18:00-21:00 at 42workspace in Rotterdam.

Our leaderboard is now final! Congratulations to RF@remotedots!

This was a Javascript coding challenge

We had a great, friendly event on 08-02-2023, 18:00-21:00 at 42workspace in Rotterdam.

Our leaderboard is now final! Congratulations to Koen!

About our coding events

42 coding challenges is an event series focusing on problem-solving coding challenges in various computer science languages and frameworks.  


Who should attend?

All genders, all seniority level software developers, data scientists hackers, & CS enthusiasts.


What’s in it for you?

  1. Through our community coding challenges, you will learn more about creative full-stack, backend, and front-end solutions that can be applied directly to your projects or job.
  2. You will have a chance to improve your programming skills, network with other developers, and discover interesting (job) opportunities at the JS community coding challenge evening.
  3. Last but not least, competing against others in the community can be tremendous fun.


About the coding challenges:

  1. The challenge type is: problem-solving
  2. You can use these languages to solve our challenges: C, C++, C#, PHP, Java, Javascript, Python, Golang, Typescript, Kotlin, Swift
  3. The length of the challenge: ±30 minutes
  4. after everyone finishes, we usually do a live coding session with drinks and snacks to learn new and interesting methods, solutions, and tricks from more senior people.



We usually have a winner at the end of the challenges, even though most of our community does not come for the spoils. A winner is the one who gets the most points the fastest.


Event Agenda

Doors open at 18:00

18:00-18:30: Welcome and rules

18:30-19:00: Coding challenge

19:00-19:30: Leaderboard update and a tech talk with a special guest

19:30-20:00: Announcing the winner & a volunteer live codes the solution

20:00-20:30: Networking


What is a coding challenge?

Coding challenges are bite-sized online problem-solving competitions. You can see a software engineer’s technical skills, problem-solving approach, and ability to think clearly under pressure.

Is this a sponsored event or a promotion?

Nope, not at all. As a community event, the organizers don’t endorse anyone nor sell attendee data.

What is the exact address?

The navigation link is: https://goo.gl/maps/VB6z8EXXkKWEkXoh7

Are you going to serve food and drinks?

Yes, we will serve some snacks and drinks.

Is this an online event?

No. It’s a physical event.

Is an RSVP required?

Yes, please. There’s a limit on how many people can join. If you can’t make it, please give your spot to someone else.

Who is allowed to participate?

You should join if you love coding and solving problems.

Is this a free event?

Yes, the event is free to attend.

Can we sign up as a team?

It is not possible to register as a team. Individuals are eligible to participate in this coding competition.

Is there anything I need to bring?

Bring your own laptop for the best setup. We don’t have laptops.