Web Developer (F/M/X)

Celsius Online
63 rue de Rivoli
75001 Paris
France
Date: 07.07.2026
Reference: AFJV-SDEV568-28987

Celsius Online

Celsius Online is a leading company in Europe in the online gaming sector. The studio was born in 2004 around the game "Renaissance Kingdoms", which became in a few years the most popular web role-playing game in Europe, translated into twenty-five languages.

The company has offices in Paris and continues to evolve its iconic titles while developing ambitious new projects.

With our technical expertise and creative skills, our ambition is to continue to grow and offer new games on different platforms, including an upcoming TCG.

Role-playing games, strategy games or mini-games, but always massively multiplayer: this is how to summarize in one sentence the projects that have been developing at Celsius Online for over fifteen years. With our experience in multiplayer games with large communities, we are currently looking for talented people to join our teams!

1 candidate • Internship Remote (00)

Internship Description

As a Web Developer, you will work on the following missions:

1- Front-End Development (HTML / CSS / Javascript):

• Integrate responsive interfaces, while maintaining the consistency of functionalities and visuals of the mockups, for the web and mobile versions of the game.
• Collaborate with the artistic and UX/UI team to integrate various visual elements into the user interface.

2- Back-End Development (PHP / MySQL):

• Develop the systems and services necessary for the game's features.
• Manage the database structure to ensure consistency in storing player information and in-game actions.
• Maintain, secure and update data storage systems.

More generally:

• Write adaptable, generic and easily maintainable code.
• Ensure the consistency of elements, the optimization of client code, the proper functioning of the game and the ergonomics of the interface.
• Verify site compatibility with existing browsers and mobile specificities.
• Resolve reported issues and bugs.
• Create clear and concise documentation of work and processes to ensure effective collaboration within the team.

Candidate Profile

What we expect from you:

1- Technical skills

• Knowledge of CSS3, SASS and Javascript languages.
• Mastery of PHP / HTML5 languages. -> PHP (back) / HTML
• Good knowledge of MySQL databases.
• Mastery of Git
• Understanding of web security issues.

2 - Transversal skills

• Excellent analytical skills and attention to detail.
• Versatility.
• Ability to work independently.
• Time and priority management.
• Team spirit and ability to collaborate with diverse profiles.
• Listening and ability to communicate effectively remotely.
• Tenacity.

Pluses

• Experience in developing web games or interactive applications.
• Understanding of UX and UI principles.
• Knowledge of JIRA and Confluence.
• Passion for video games, especially retro and browser games, and/or role-playing games.

Additional Information

Start date: as soon as possible
Duration: up to 6 months

This internship is offered entirely remotely, just like the rest of the team. Good autonomy and ease with remote working tools will therefore be essential to succeed in this position. We provide all the necessary means to ensure smooth integration and effective support throughout the internship.

Important: this organizational method must be agreed upon with the educational institution, and the internship agreement must explicitly mention it.

Provide

CV, cover letter, references, website (if applicable)

To: Nadège PANZA