Backend PHP developer with Linux focus
About Mixvoip
We are Mixvoip, a vibrant Luxembourg-based company that provides Cloud Telephony, Smart Networking, and High-Speed Internet services. We believe in offering our customers a fresh take on communication systems, and that’s where you come in!
About the role
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.
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.
Key responsibilities
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
What do we need from you?
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
What would make you stand out?
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
A new way to apply: join Mixvoip’s success story
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.
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.
Information
Backend PHP developer with Linux focus
Permanent (CDI)
13/03/2026
Steinsel
High School
Full Time

