Junior VoIP Engineer

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Junior VoIP Engineer

Are you looking to give your development career a new twist? Get hands-on experience in SIP development, supported by your colleagues, while working on the infrastructure of our VoIP telephony platform.

Full-time / Part-time · Groningen

We are looking for someone who has an affinity with programming and wants to learn about Voice-over-IP (VoIP) and SIP technologies. Experience with VoIP or SIP is not required, you’ll learn that here! You will be working as part of our infrastructure team, who maintain the backbone of our telephony platform VoIPGRID. Within this team, you will be collaborating closely with and mentored by our two other SIP stack developers. You will get plenty of opportunities to learn on the job in a supportive environment where making mistakes is mandatory (and we’re there to catch you when you do).

You will learn to develop and maintain our telephony stack with a focus on SIP, as well as create new features and introduce new technologies.

We support telephony over traditional desk phones, a mobile app for iOS and Android, and a progressive web app (WebRTC). We are active in four countries (the Netherlands, Belgium, Germany, and South-Africa), with servers in The Netherlands and South-Africa (meaning some fun latency issues between servers, databases and customers!) Our customers expect their telephony to work 24/7, so all our infrastructure is redundant. Our SIP stack consists of OpenSIPS and Asterisk, with a MySQL database and a Python/Django web app. We also have a custom Golang application that sits in between the web application and the telephony layer. Last but not least we are slowly moving microservices and other services to kubernetes. 

As our new colleague, you are someone with some experience or an education in programming and who wants to learn specifically about SIP development. This is a great opportunity if you want to get your first practical experience or if you want to focus your career by taking a deep dive into a specific tech stack. You know at least one programming language but are ready and open to learn more. Troubleshooting and solving problems that come up are things that bring you joy. You are not afraid to ask questions or ask for help - you’ll be joining a team of people who enjoy working together and helping each other out, so there is a lot to learn from each other. If you love open source projects, that’s an extra bonus. 

Your professional profile


  • Are proficient in English, our working language. The team you join is international and there are currently 10 nationalities at Spindle

  • Have a Bachelor’s degree or one year work experience in programming

  • Know your way around a linux terminal

  • Know at least one programming language

  • Are eager to learn and not afraid to make mistakes

Bonus points if you:

  • If you know or have experience with Python or Go

Our stack:

  • Asterisk

  • Opensips
  • Python
  • Golang
  • Mysql
  • Django
  • Kubernetes
  • Saltstack
  • Prometheus/Grafana
  • Homer
  • Proxmox/KVM
  • Debian

About Spindle

Devhouse Spindle is a growing and ever-changing organization on a mission to connect the world using open and free communication. With almost 60 colleagues, we develop the tools that make this possible such as VoIPGRID, our award winning telefony platform. Alongside our VoIP platform we develop an app (both Android and iOS versions), a webphone, and a browser plugin which allow you to use the platform wherever you are.

Next to the tools we develop, we also connect people through the foundation, 48percent.org and the open source community, the Open VoIP Alliance. Spindle is located in Groningen, a beautiful city known for its innovation and the second fastest growing tech city in the Netherlands.  

Working at Spindle

If you look around the office, you’ll notice we do things a bit different around here:

  • We organize ourselves using a system called Holacracy. We believe every colleague is able to contribute to the organization rather than relying on a traditional hierarchy. Having no managers comes with extra responsibility to take ownership of your work and set priorities that help to further the organization.

  • We work with a “build, measure, learn” mentality and open mindset. We recognize that not everything you do is going to work right away. We praise experimentation and reward trying something new, even if the lesson is to not try it again.
  • We have an open and transparent salary system. Every colleague is placed in the pathway and a level best fitting their education, experience, and visible behavior. We encourage growth and have clear guidelines and expectations for doing so.
  • We are a diverse and inclusive team of international coworkers. We value the differences that each person brings to the table and think that it's those differences that strengthen our organization.
  • We strongly believe in open source. We show this by open sourcing our code when possible, using other open source projects for our VoIP platform, contributing to projects, and we have even started the Open VoIP Alliance to encourage collaboration when it comes to VoIP open source software.

What we offer

  • A relaxed and welcoming culture with celebrations, events, and trips

  • A competitive salary and good pension benefits
  • An annual study budget and study days for personal and professional growth
  • Other benefits that contribute to your health, well-being, and work/life balance 

Join the team

You can apply for this job opening using the button below.

Want to know more about this job, the employee benefits, or Spindle? Don’t hesitate to contact Dick on 050-8009078 or teamup@wearespindle.com.

Please note that we are currently not hiring for remote work. You need to have an EU Working Permit (Orientation Year Visa not included) in order to be applicable for this position.