Duration: 6 months

Region: Europe

Mode: Remote

Fees: TBD


Our client, a software startup based from Germany, is looking for freelance developers to help them push the boundaries of mobile telephony and contribute to a wide range of exciting project.

Their cloud-native VoLTE/IMS solutions allow mobile network operators to offer innovative voice services across all data networks – from 4G, 5G to WiFi and others.

Key Responsibilities:


  • IMS Development: Design, develop, and maintain cloud-native VoLTE/IMS solutions using C programming language and other relevant technologies.
  • Telco Expertise: Apply telco/IMS experience to ensure the reliability, scalability, and performance of voice over internet services.
  • Compliance: Adhere to industry standards and specifications, including 3GPP specs, to ensure interoperability and compliance with regulatory requirements.
  • Deadline Adherence: Manage project timelines effectively, consistently meeting deadlines and delivering high-quality work within agreed-upon schedules.
  • Problem Solving: Identify technical challenges and propose innovative solutions to optimize performance and functionality of VoLTE/IMS solutions.
  • Collaboration: Collaborate with cross-functional teams, including network engineers, QA testers, and product managers, to align development efforts with project objectives.?


Professional background


  • Strong interest in and understanding of telephony.
  • Telco/IMS experience
  • Proficiency in C programming language
  • Experience with signaling standards such as SIP, DIAMETER is a plus.
  • Fluency in English; reading 3GPP specs should be a part of your skillset.
  • Proven track record in adhering to deadlines and keeping projects on track.

Our Technology Stack Includes (NICE-TO-HAVE):

  • Kamailio, RTPEngine, FreeSwitch, OpenSIP
  • Redis, MySQL, Docker; Kubernetes, RTP
  • Proficiency in Python is a plus

Tagged as: 3-5 Years, 5+ Years, C#, Kubernetes, Python