• Full Time
  • London

Senior VoiP Developer 

Location: London
Salary: £60k-£70k (+Health Insurance, Mobile, Laptop)

The Client is a CaaS provider with a HQ in Brussels with Offices in the UK, USA(x3) and Romania, around 140 employees. As one of the most exciting companies in the VoIP tech space, the client is growing fast.

 You will join a multi-skilled team that, based on open source technology, is delivering the heart of products and services. They are looking for a fearless innovator who is able to tackle complex challenges whilst providing industry-leading solutions. Current stack: Java, C code, MySQL, Cassandra and RabbitMQ.


Key Responsibilities

  • Build manageable, scalable and strong messaging and voice services using Java and C
  • Write services for SIP, SMPP, T.38 protocols and many more
  • Be an active participant in discussions about design and architecture
  • Develop new features and optimize existing ones
  • Using feedback to develop and create optimally performing and scalable solutions
  • Analyze project requirements as a team
  • Rapidly fix issues and bugs whilst creating automatic tests to avoid these in the future
  • Be an advocate for best practices in software development (TDD, high code coverage unit and integration tests, etc.)


  • Powerful knowledge of SIP, SMPP
  • Strong C, C++, Java and Perl skills- you could do this in your sleep
  • A disciplined attitude towards testing and quality assurance
  • Ability to design software for performance and scalability
  • Knowledge of test automation
  • Completely at home with a Linux environment
  • To be a team player, not afraid to communicate clearly on issues and progress
  • To be comfortable working against deadlines

 Positive if you have:

  • Working knowledge of asterisk and Kamailio
  • Experience with Java 8, Hibernate and Spring 4 Experience with message and job queuing services (RabbitMQ)
  • Experience with MySQL
  • Experience with Cassandra
  • Great communication skills in English 

To apply please send your CV to Connor Hanley at Syntony (Search & Selection) Ltd