At a Glance
- Tasks: Develop a cutting-edge cloud PBX platform with core VoIP functionality and modern interfaces.
- Company: Join Yottavox, a forward-thinking tech company shaping the future of telephony.
- Benefits: Enjoy competitive salary, remote work, and the chance to build from scratch.
- Other info: Great opportunity for career growth in a dynamic, remote working environment.
- Why this job: Be part of an innovative team and influence a new platform's development.
- Qualifications: Strong VoIP background and experience with PBX or SIP systems required.
The predicted salary is between 36000 - 60000 € per year.
We are building Yottavox - a modern cloud-hosted PBX platform designed for clarity, performance, and scalability. The product is currently in development and we are now hiring a talented Full-Stack PBX/VoIP Developer to join at an early stage and take a key role in the build.
This is a unique opportunity to work on a new platform from the ground up, without legacy constraints, and help shape a clean, modern telephony system built for real-world operators and end-users.
The Role
You will be responsible for developing the core PBX functionality, APIs, and admin interface. Working closely with design and product, you'll build a reliable, secure, multi-tenant VoIP platform with a strong focus on quality and long-term maintainability.
Key Responsibilities
- Core PBX & VoIP Development
- Build call routing, extension logic, IVR, queues, voicemail, and CDR workflows.
- Develop predictable, efficient, secure VoIP behaviour with multi-tenant capability.
- Backend Architecture & APIs
- Design and implement scalable backend services and REST APIs for provisioning, configuration, and reporting.
- Follow clean architectural patterns and maintain high coding standards.
- Frontend Implementation
- Develop a modern admin interface using React/Vue (or similar).
- Work from wireframes and collaborate with design to deliver a clean, intuitive experience.
- Integrations & Infrastructure
- Integrate with SIP trunk providers, manage number routing and failover logic.
- Build tooling for diagnostics, monitoring, real-time events, and system health.
- Quality, Security & Stability
- Ensure telecom-grade reliability with proper SIP/RTP handling, NAT traversal, SRTP/TLS, fraud controls, and error management.
- Optimise for low latency, resilience, and predictable performance under load.
- Documentation & Technical Clarity
- Maintain clear documentation for APIs, data models, call flows, and system components.
- Ensure all work is structured, readable, and easy to maintain or extend.
- Collaboration & Delivery
- Work closely with design, product, and a fractional architect.
- Communicate clearly, follow consistent patterns, and deliver high-quality implementations without micro-management.
- Environment Setup & Testing
- Support containerised dev environments, basic CI/CD, and automated tests for critical flows.
- Prepare for staging and early-access deployment.
Required Experience:
- Strong VoIP engineering background and experience building PBX or SIP-based systems.
- Deep knowledge of SIP, RTP, media handling, and related telecom protocols.
- Hands-on experience with Asterisk and ideally FreeSWITCH.
- Solid backend development skills in Node.js, Go, Python, or C++.
- Strong understanding of REST APIs, authentication, and database design.
- Experience with React, Vue, or similar front-end technologies.
- Familiar with Docker, cloud hosting environments, and modern DevOps practices.
- Good understanding of VoIP security (TLS/SRTP, NAT traversal, rate limiting).
Nice to Have:
- Experience with multi-tenant SaaS architecture.
- Knowledge of SIP trunking, number routing, failover logic.
- Familiarity with call recording, CDRs, and telecom observability tools.
- Experience integrating with SBCs or media servers.
What We Offer:
- Competitive salary based on experience.
- Remote working.
- A chance to build a new platform from scratch - no legacy code.
- Early technical influence with significant autonomy.
- Opportunity to grow into a senior or lead role as the platform scales.
Job Type: Fixed term contract
Contract length: 12 months (with strong potential for permanent on review)
Benefits: Casual dress, Work from home
Work Location: Remote
Full-Stack PBX / VoIP Developer (Cloud PBX Platform) in Sheffield employer: Yottavox
At Yottavox, we pride ourselves on being an innovative employer that offers a unique opportunity to shape a cutting-edge cloud-hosted PBX platform from the ground up. Our remote work culture promotes flexibility and autonomy, allowing you to contribute significantly without the constraints of legacy systems. With competitive salaries and clear pathways for career advancement, we are committed to fostering your growth as we scale our exciting new technology.
StudySmarter Expert Advice🤫
We think this is how you could land Full-Stack PBX / VoIP Developer (Cloud PBX Platform) in Sheffield
✨Tip Number 1
Network like a pro! Reach out to folks in the industry, attend meetups, and connect with potential colleagues on LinkedIn. You never know who might have the inside scoop on job openings or can put in a good word for you.
✨Tip Number 2
Show off your skills! Create a portfolio showcasing your projects, especially those related to VoIP or PBX systems. This gives us a tangible way to see what you can do and how you think about problem-solving.
✨Tip Number 3
Prepare for interviews by brushing up on common technical questions and scenarios related to VoIP and PBX development. We love candidates who can demonstrate their knowledge and passion for the field during our chats.
✨Tip Number 4
Apply through our website! It’s the best way to ensure your application gets seen by the right people. Plus, it shows us you're genuinely interested in being part of our team at Yottavox.
We think you need these skills to ace Full-Stack PBX / VoIP Developer (Cloud PBX Platform) in Sheffield
Some tips for your application 🫡
Show Your Passion for VoIP:When writing your application, let us know why you're excited about working in the VoIP space. Share any personal projects or experiences that highlight your enthusiasm for telephony systems and cloud technologies.
Tailor Your CV and Cover Letter:Make sure to customise your CV and cover letter to reflect the specific skills and experiences mentioned in the job description. Highlight your expertise in PBX development, SIP protocols, and any relevant technologies we use at Yottavox.
Be Clear and Concise:We appreciate clarity! Keep your application straightforward and to the point. Use bullet points where necessary to make it easy for us to see your key achievements and skills at a glance.
Apply Through Our Website:Don’t forget to submit your application through our website! It helps us keep everything organised and ensures your application gets the attention it deserves. We can’t wait to hear from you!
How to prepare for a job interview at Yottavox
✨Know Your Tech Inside Out
Make sure you brush up on your VoIP engineering skills, especially around SIP and RTP protocols. Be ready to discuss your hands-on experience with Asterisk or FreeSWITCH, as well as your backend development skills in Node.js, Go, Python, or C++. This will show that you're not just familiar with the tech but can actually apply it.
✨Showcase Your Problem-Solving Skills
Prepare to talk about specific challenges you've faced in previous projects, particularly around building PBX systems or handling telecom protocols. Think of examples where you had to optimise for low latency or ensure telecom-grade reliability. This will demonstrate your ability to think critically and solve real-world problems.
✨Get Familiar with Their Product Vision
Since Yottavox is a new platform, take some time to understand their goals for clarity, performance, and scalability. You might even want to think about how you would approach building core PBX functionality or developing a modern admin interface. Showing that you align with their vision can really set you apart.
✨Communicate Clearly and Collaboratively
During the interview, focus on demonstrating your communication skills. Since the role involves working closely with design and product teams, be prepared to discuss how you collaborate effectively. Share examples of how you've worked in a team setting to deliver high-quality implementations without needing micromanagement.
