Senior Site Reliability Engineer

Are you looking to join a highly ambitious international technology startup and work on cutting edge technology? Do you want to build a career in technology but love to solve real life communications problems? Are you looking for a company that will invest time in your development, support your professional growth and listen to your ideas? If the answer is yes, we urge you to apply for a position with Telestax!

At Telestax, we connect an innovative community of customers, partners, and contributors to deliver trusted, high-performing technologies that solve business problems. Telestax is the leading CPaaS enabler for communications service providers and creator of the award-winning Restcomm API platform. Originating in the largest industry open source community, managed by Telestax, Restcomm has been tested by over 10,000 telecom developers and contains over 6 million lines of code.

Job Summary

Telestax is currently seeking a site reliability engineer who will be responsible for designing, coding, and operating tools and systems to improve the stability, scalability, availability, and latency of the world’s best CPaaS enablement platform. This team is at the core of deploying distributed, scalable system foundations and ultimately designing and striving for >=99.95% uptime and horizontal scalability. Candidates in this space should have a strong desire to drive innovation by deploying, operating monitoring, scaling, and troubleshooting feature rich, scalable systems that are conducive to evolution. Our products must handle continual core network traffic from Tier 1 operators, CPaaS companies and large enterprises.

As a site reliability engineer, you will be driven to deploy, monitor, and scale high performing, low latency, highly available and scalable microservices and be concerned with throughput, latency, payload fidelity, distribution, and scale. You will also stay up to date with innovative technologies that enable deployment and management of the products in the cloud.

You will also work closely with architecture, backend and frontend engineers to advocate sensible, scalable, systems design and share responsibility with them in diagnosing, resolving, and proactively preventing or troubleshooting production issues.

This position reports to the Team Lead of the Site Reliability Engineering Team.

Occasional travel may be required for meeting distributed team members, conferences, and other events.

Primary Job Responsibilities    

As SRE at Telestax you will:

  • Design and document systems, including writing and reviewing code, to ensure reliability and stability of solutions within your team’s domain
  • Design and document systems, including writing and reviewing code, to automate solutions deployment within your team’s domain to reduce toil
  • Manage Cloud provider infrastructure, system deployments, and product releases
  • Writing automated test for your infrastructure code
  • Demonstrate and promote best practices for teams using Cloud platforms
  • Monitor the Restcomm Cloud platform and Cloud infrastructure, responding to incidents, correcting and improving systems to prevent incidents and planning capacity
  • Participate in on-call rotation schedules
  • Comply with service SLAs and SLOs and effectively handle events such as incidents and blameless post mortems
  • Undertake measured, strict, troubleshooting of complicated systems and potentially resolve time-critical incidents
  • Work closely with other team engineers to design services that are reliable, scalable, manageable and supportable
  • Excel as an engineer and be a productive member of the team where leadership is a behavioral trait, not a title

Required Skills

  • Experience using at least one cloud environment; AWS, GCP, Azure, Softlayer or OpenStack. Certifications are a plus
  • Practical experience in a production DevOps environment where dependent teams need to ship rapidly and often
  • Practical experience deploying, monitoring, scaling, and operating Java JVM Based microservices
  • Understand the Linux OS at both high and low level
  • Proficiency with a scripting language like Python and Bash
  • Experience with Infrastructure as a Code such as Terraform, Ansible
  • Experience with monitoring tools such as Datadog, Prometheus, Graphana, or other
  • Experience with Container technologies – Docker, Kubernetes, Nomad, AWS ECS
  • Experience with CI/CD practices (Pipelines, graceful shutdown, A/B upgrade, canary upgrades, …) and tools (Jenkins, Spinnaker etc…)
  • Experience with SQL (MySQL) and NoSQL databases (Cassandra/MongoDB), in memory data grid technologies (Redis, Infinispan) at scale

Desirable Skills

  • Experience with API Gateway
  • Experience with Serverless
  • Automated testing experience applicable for infrastructure (testinfra, molecule)
  • Experience with Java, JavaEE (JBoss Application Server), Spring, Spring Boot
  • Knowledge of Messaging & Real-Time Communications – SIP, RTP/RTCP, XMPP, SMPP,  PCAP, …
  • Experience with VoIP diagnosis tools  – TCPDump, Wireshark, VoIPMonitor…
  • International experience (working in or with multi-cultural distributed environments)
  • Remote Experience
  • You have worked in an Agile development environment
  • Ability to work in a fast paced environment with fast moving team and changing requirements
  • Ability to work with independent thinkers who are highly technical and passionate
  • Technical writing skills
  • Ownership: Act as one company—one team: Care first about Telestax, not your role or your department. Own your stuff, no question, but go beyond your role; help before you are asked. Everything you need to make things happen, you do it


  • Rennes or Lannion, France
  • Remote Telestax virtual office

At Telestax you will enjoy working with real-time communications and cutting edge technology in a growing company and fast moving environment. You’ll also have the ability to work remotely and experience strong collaboration amongst small, focused, globally distributed teams for better customer impact. You’ll be part of a company that strives to build an inclusive culture where everyone is continuously seeking to improve both themselves and the system they operate in.


Telestax is proud to be an equal opportunity workplace and an affirmative action employer. We review applications for employment without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, ancestry, citizenship, age, uniformed services, genetic information, physical or mental disability, medical condition, marital status, or any other basis prohibited by law.

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