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Senior Full-Stack Engineer (f/m/d)

NFON

NFON

Lisbon, Portugal
Posted on Jul 9, 2025
Your new role
Are you ready to shape the future of business telephony? As Senior Full-Stack Engineer (f/m/d), you will play a key role in developing and enhancing NFON’s cloud-based phone system. You will be instrumental in designing and implementing scalable backend services, ensuring high availability and performance. Your contributions will directly impact our product's reliability and efficiency, empowering businesses across Europe. This position offers an exciting opportunity to work with cutting-edge technologies in a collaborative and agile environment. If you are passionate about clean code, software architecture, and high-quality standards, this is the role for you!
The work you‘ll do
  • Further develop and maintain existing JSON REST APIs
  • Design and implement interfaces that connect seamlessly with existing back-end functionalities, utilising RESTful Web Services
  • Define and implement test strategies to ensure high software quality
  • Integrate services into our CI/CD pipeline, extending and improving automation workflows
  • Ensure knowledge transfer and close collaboration with your colleagues to help everybody improve
  • Support deployment processes, including occasional out-of-hours assistance
  • Collaborate closely with cross-functional teams, including frontend & backend developers, DevOps, UI/UX colleagues and QA engineers to create captivating and user-friendly designs that guide and excite our customers
  • Work in a self-organised agile team, contributing to a culture of continuous improvement
The qualifications you need
  • Bachelor's degree in computer science or relevant experience in software development
  • Strong communication skills in English, with the ability to explain complex ideas clearly
  • Proven experience with Go (Golang) and deep understanding of its specifications
  • Proficiency in modern server-side technologies and tools, including Postman, REST, JSON, YAML, OpenAPI, MySQL, PostgreSQL
  • Passion for software architecture, clean code, testing and best practices
  • Strong problem-solving skills with a proactive attitude toward tackling challenges as well as strong feedback culture
  • Experience with API-Monitoring (Grafana/Prometheus) and JIRA, Bitbucket, and Bamboo
  • Ideally skilled in front-end development with HTML5, CSS3, TypeScript, Angular, plus testing (Jest, Jasmine, Spectator, codeceptjs)
What we can offer you
  • An unlimited fixed-term contract
  • Flexible working hours and the option to work hybrid (2 days/week in the office)
  • Cozy and large workplaces with modern equipment and cordial colleagues in Lisbon (Barata Salgueiro 37) – super central
  • Funding of educational trainings and Rosetta Stone language courses
  • Additional vacation days (25 instead of 22)
  • One of the best health Insurance with great coverage (including family members — free of charge (after probation period)
  • Meal allowance card and Pizza discounts
  • Subsidy of Urban Sports Membership
  • Public transportation subsidy
  • Laptop of your choice (Apple, Windows or Linux)
  • Regular team and company events
  • Fruits and beverages in Office
  • Referral Programmes - Earn up to €3,000 bonus by referring top talent!
About us

NFON who?

We’re NFON – a leading European provider of integrated business communication with a focus on AI-based applications and as a licenced telecoms company active in 15 European countries. Since 2019 we are listed in the Prime Standard segment of the Frankfurt Stock Exchange, have nine branch operations and are working together with over 3,000 partners. Every day, we support around 55,000 business customers in Europe with intuitive communication solutions that make their businesses more efficient and flexible.

What we do…

As a long-term partner for small and medium-sized businesses, we combine technological innovation with user-friendly and efficient business communication solutions. With both AI-based technologies and operational excellence, we are enabling companies to harness the full potential that artificial intelligence offers – for optimised processes, more precise customer interactions and new growth opportunities. With its core product, the smart cloud communications platform, we are offering hassle-free voice calls, simple video conferencing and seamless integration of CRM and collaboration tools for small and medium-sized companies. All of NFON’s cloud services are operated in certified data centres in Germany, with 100% of their energy needs covered by renewable sources.


How & why we do it

Our vision is to rethink business communication, inspire and connect people to grow together sustainably. For that we need innovative ideas and people who get things done & never get discouraged. If plan A doesn’t work, the alphabet still has 25 other letters to choose from. There is one thing that builds the foundation of everything we do – and that’s respect. Whether it is towards our employees, our partners or our customers. We value each other’s commitment and listen to diverse opinions. Of course everyone has personal goals. But at the end of the day what counts is the success of the overall team. We work as a team and learn from the people around us.

Diversity is at our core.

NFON is an equal opportunity employer and does not discriminate on the basis of ethnicity, religion, color, national origin, gender, sexual orientation, gender identity, age, marital status, veteran or disability status.