FAQs - Reply Code Challenge Standard Edition

Participants & Registrations

1. Who can take part?

The Reply Code Challenge is an online coding competition open to passionate coders from aged 16 years and above, from all over the world. There will be two challenges, one dedicated to Replyers and one to professionals and students outside Reply.

2. Can I arrange a mixed team of Replyers and externals for this coding game?

No, unfortunately you can’t. As there will be 2 challenges, we’ll also have 2 leaderboards, so we’ll keep these competitions separated.

3. If I register on the platform, am I registered for the competition?

No, you need to join a team, create your own, or join the random queue to play on 15th March. By registering on the platform, you’ll get updates on upcoming online challenges.

4. Is there a registration fee?

No, this coding challenge is completely free!

5. When do the registrations close?

You can register until 14th March, 12:00 noon - EXTENDED - at 14.00pm CET - March 15th.

6. I’ve registered, but I have no teammates. What can I do?

Once you’ve registered, you can join a team, from one or ask for the ‘random queue’ to assign you one.

7. How do I change my registration details?

To update your details at any time, log into your profile and click “Edit profile”, or follow this link.

8. How do I cancel my registration?

You can send your cancellation request to challenges@reply.com.

9. Is it an online only code game?

Yes, it is an online only coding competition.

Forming a Team

1. How can I form my team?

Just like other code games, to form your team, log in to the Reply Challenges platform, click “Team up” button and select “Create new team”. Once you’ve formed a team, you’ll see it when you log in to the platform. You’ll also be able to choose a team name and invite your friends. Just fill in their email addresses and send the invitation. Remind that Replyers will play in a challenge reserved for them, that’s why mixed teams are not allowed.

2. How many people can be in a team?

Your team can have 2, 3 or 4 people. A team cannot consist of 1 person, so remember to invite friends or colleagues to join your team or join the ‘random queue’.

3. I don’t want to form a team, what can I do?

No problem. You have until midnight CET on 13th March to join someone else’s team or ask for the ‘random queue’ team assignment. If you join the random queue you’ll receive a mail with the name of your team before the challenge.

4. Can I change who’s on my team before the challenge day?

No, but you are free to leave your current team. They won’t receive any notification, so remember to tell them.


1. How will we get updates about the Reply Code Challenge?

You’ll get some mails before and after the challenge, so check your mailbox regularly. You can always message the Reply Code Masters during the challenge via chat if you have questions.

2. Which language(s) do I need to speak?

All communications will be in English. Though you and your teammates can speak whatever language(s) you like! ☺

Reply Challenges

1. What browsers are supported?

The platform supports the latest version of Chrome, Explorer, Firefox, Microsoft Edge and Safari. If you’re not sure what version you have, you can check here.

2. Something’s wrong with the platform. What should we do?

Try reloading the page, then try clearing your cache and cookies. If you’re still having problems, please message the Reply Code Masters on chat or email challenges@reply.com.


1. Can we train for the Reply Code Challenge?

We strongly recommend you practice on the training problem before the Reply coding game takes place. That way, you can better understand the type of challenge you might get and how to submit solutions.

2. How do we access the training problem?

Just visit the Reply Challenges platform any time. You can upload as many solutions as you want, as many times as you want. The training problem submission works just like the real challenge, except you’ll play alone and not in a team.

3. How do we submit a solution?

Submit a solution by dragging and dropping it or uploading it from the computer. Each submission contains at least one output file and at least one source code file. Note, you’ll always have to upload the source file, but it’s not mandatory in sandbox mode.

4. Will I see a score when I submit a solution?

Yes. You’ll see a list of scores of all your submissions.

5. Will there be a leaderboard in the training area?

No, but you’ll see your submission scores.

6. What if we have a question a bout the problem statement?

You can message the Reply Code Master via chat.

During the Reply Code Challenge

1. When will you publish the problem?

On 15th March, at 4.30pm CET, Reply will publish the problem statement on the challenge platform. It will include the input files you can download from the challenge platform, where you’ll also submit your team’s solution files.

2. When is the leaderboard updated?

We’ll update the leaderboard regularly to show how teams are performing. We’ll also freeze it 30 minutes before the challenge deadline (but we’ll continue to updates scores).

Technical requirements, submission and scoring

1. What programming language and tools can we use?

Just like most coding challenges, you can use your favourites.

2. What are the other computer/technical requirements?

You’ll need your own computer with an internet connection

3. How do we upload a solution?

Your team submits solutions by uploading a file to the challenge platform.

4. How many solutions can we upload?

Your team can submit as many solutions as they like, any time during the challenge. We encourage to submit solutions as soon as you can, to check if your solution is working.

5. How do you calculate the scoring?

We’ll calculate your team score by summing up the maximum score of each valid input file; the scoring system awards the solutions that best optimize the problem. Reply Code Masters may, at any time, reject a solution and invalidate its score. To settle ties, we’ll take time into account. Each output file must be an UTF-8 plain text file.

6. What should our source code look like?

Your team can use publicly released libraries and tools, but your solution must use original code. To be valid, every submission must include a file containing the source code of the program you developed to generate the output. Each source code file must be an UTF8 plain text file, or an archive of UTF-8 files.

7. Can we use any development and execution environment?

Yes. There are no restrictions on the development environment or programming language you use during the contest. You simply write programs to solve a task and submit the results as a text file to the challenge platform. You’re responsible for compiling and running your code on your own computer(s).

Winners and Rewards

1. Who wins?

At the end of the code game, the Reply Code Masters will review and validate the best scoring submission from top ranked teams on the leader board. The Reply Code Masters’ decisions regarding the rules of the coding competition are final.

2. When will you announce the results of the Reply Code Challenge?

We’ll publish a full list of results and notify all finalists no later than one week after the day of the challenge.

3. What's the prize?

At the end of the challenge, the Reply Code Masters will review and validate the best scoring submission from top ranked teams on the leader board. Each member of the winning team will win a Mac Book Pro™. The team placed second in the raking will win an Apple Watch Series 4™, the team placed third in the ranking will win Apple Air-pods™. The Reply Code Masters are sovereign for enforcing the rules of the contest and deciding the prizes. We’ll send the winners details of how to claim their prize.

Code Masters and fair play

1. Who are the Reply Code Masters?

Reply Code Masters wrote the problem and are responsible for enforcing all coding challenge rules. They’ll review submissions from teams and award prizes. They may exclude any participants or teams at any time, for not following competition rules.

2. What do we do if someone’s cheating or behaving badly?

We want to make training sessions and the challenge fair for everyone. So never stop others from taking part – for instance, by overloading the challenge platform, or sending files containing malware, viruses or other code intended to interrupt, destroy or limit operation of platform, software, hardware or telecoms equipment. This will result in instant disqualification. If you’ve spotted any cheating or unfair behaviour, email challenges@reply.com