Backend PHP developer

You will join the PBX development team and work on the backend systems that power our cloud-based phone platform. This is not a traditional web development role. There is no frontend, UI, or CSS work. Most of the work happens in backend services, automation scripts, and configuration generation interacting directly with our VoIP infrastructure. You will write PHP code that generates configuration files, automates device provisioning, integrates with internal and external APIs, and implements new features for our PBX platform. Much of the code runs outside of a browser context through CLI tools, background workers, or scheduled jobs. Because of this, working comfortably in a Linux environment is important. This role also requires a regular on-site presence at our office in Luxembourg. Close collaboration with the team and hands-on interaction with the systems you will be working on are an important part of the position, so this is not a remote role. You will not be thrown in alone, but you are expected to take ownership of what you build, understand how it interacts with the rest of the platform, and continuously improve the systems you work on., * Develop backend features for our PBX platform

• Implement new call routing and configuration capabilities
• Build automation for provisioning VoIP devices (Yealink, Gigaset, Grandstream)
• Integrate internal systems and external vendor APIs
• Develop CLI tools and background jobs used in the platform
• Generate and maintain configuration templates using Twig
• Troubleshoot and improve backend automation interacting with VoIP infrastructure
• Document systems, code, and operational workflows

• Strong PHP fundamentals and backend development experience
• Comfortable working in a Linux environment
• Experience building backend services or automation tools
• Familiar with API integrations and structured data formats
• Comfortable working with CLI tools, cron jobs, and background processes
• Methodical troubleshooting and clear communication
• Able to take ownership of systems you develop
• Comfortable using AI coding tools (e.g., Claude) as part of daily work, * Experience with VoIP or telecom systems
• Familiarity with SIP, PBX systems, or Asterisk
• Experience generating configuration files or working with templating systems
• Experience with Docker-based development environments
• Understanding of networking basics (IP, routing, firewalls)
• Interest in infrastructure-oriented backend systems
• Strong documentation habits and clean engineering practices

Join Mixvoip and you won’t just be connecting businesses to high-speed internet, fiber, satellite, phone, or mobile networks, you’ll be connecting people, forging relationships, and making a real difference in our story. So, if you’re prepared to embark on an engaging journey and play a pivotal role in Mixvoip’s saga, here’s an unconventional route to apply We invite you to record a brief presentation video with your smartphone. Share why you’re drawn to this role or pose any questions or doubts you might have. It’s about keeping the conversation open and engaging! Please remember to attach your CV in PDF format too. Instead of a conventional cover letter, we’d like you to employ an AI of your choice. This not only mirrors our technology-focused approach, but it also allows you to showcase your adaptability to new tools. It’s less about the letter, more about your interaction with AI that we’re keen on.

Eager to join the ride? We can’t wait to hear from you!

PS: Want to know who you’ll be journeying with? Meet me, Christophe Laures I’m 33 years old and have been part of Mixvoip for the past 10 years. Today, I lead the development of our PBX platform, working with the team to create the best possible experience for our customers. My main focus is driving the evolution of our newest PBX system so that our customers always have a reliable and versatile communication tool they can depend on. I enjoy solving complex challenges and finding clean, practical solutions that make a real difference. I’ve always been passionate about computers and technology, which is what originally led me into this field. Outside of work, I enjoy spending time outdoors. You’ll often find me hiking with my wife and our dog, recharging and getting ready for the next technical challenge. And on rainy days, I’m usually at home playing computer games.