• Location: Vienna/Austria, Remote Europe
• Job Type: Full time
• Experience: 5+ years
• Skills: SIP, RTP, Networking, Linux, Docker, AWS/Google Cloud, Customer Support
• Salary: 84 k€ annually, plus employee stock options
• Apply: jobs@sipfront.com

About the role

Join Sipfront as Senior VoIP engineer, supporting our customers test projects!

At Sipfront, we automate testing of real-time communication services for telecom operators and vendors. Their operations teams will know at all times what works in their system and infrastructure and what doesn’t, giving them peace of mind in their daily routine and full information when something happens. Likewise, their developers can focus on shipping features without fearing nasty regressions.

To achieve this, we automatically simulate end-to-end phone calls for our customers and check if connections get established and quality matches expectations.

We are looking for an ambitious VoIP engineer with a passion for software test automation and an ambition to manage people, who is helping our customers to implement and operate their testing and monitoring scenarios on our platform, and is working with us to design and implement new test features and troubleshooting tools to keep them excited about our products.

How to apply

Send us an email including

• a link to your LinkedIn profile or a CV, and whatever information you consider relevant
• a link to your Github or another summary of your accomplishments

About you

• You are eager to join a growing team of engineers in an early stage, where you can heavily influence the trajectory of the product and the company.
• You embrace a work environment where we share our knowledge internally and help each other solve our challenges, while maintaining a “get things done” attitude.
• You love to work closely with small to huge global internet and telecom companies, improving their automated QA work-flows.
• You have 5+ years of developing and/or operating telecom platforms, and know your way around troubleshooting SIP call flows and RTP streams.
• You have a talent to manage people, both on our customers’ side as well as internally, building a technical team within Sipfront.

What the job involves

• You will work with our Sales team to set up and perform technical demos and proof-of-concepts with potential customers, and design work flows and processes to streamline their onboarding. Your creativity and problem solving skills will allow you to model test cases fitting our customers’ requirements.
• You will train customers on the Sipfront service and troubleshoot issues customers might be experiencing while running their tests.
• You will evaluate and set up SIP trunks with local and global carriers such as Twilio, Bandwidth and Tier-1 carriers, and SIP devices such as 3CX and other PBXes to extend our interconnection network and certification environment.
• You will improve our test agents by leveraging existing features of already established tools such as baresip, sipp, kamailio and rtpengine, and by introducing new tools to cover other protocols such as diameter in the future.

Our stack

We run our product stack on AWS, trying to leverage on existing AWS services rather than operating auxiliary services by ourselves. Our components involve:

• A web application implemented in Perl/Mojolicious
• Microservices for message queue communication and data processing in Perl
• Lambda functions in Python and Go
• System observability based on Jaeger and Datadog
• Elasticsearch, Postgresql, Timestream DB, IoT Core, Kinesis running on AWS
• Kamailio, rtpengine, baresip, sipp and codecept within Docker containers on AWS ECS and bare metal

Why you should join Sipfront

Our mission is to improve the quality of real-time communications. We, the founders team, are engineers by heart, and we love working with other engineers.

If you join, you can collaborate with our customers from the top Fortune 100 down to startups around the globe, and you will be able to breathe WebRTC, VoIP, Machine Learning and other exciting technologies besides your main work focus. You will work with top engineers on cutting-edge technology, utilizing your past experience and improving your skills. As the company grows, you will have the opportunities to either take responsibility for a team or develop into an expert engineering position.

Our remuneration packages include stock options, allowing you to benefit from future company success. Everyone’s contribution is recognized as part of the company’s performance.

About the interview

We’re trying to keep the hiring process as lean and efficient as possible for both sides. We split the process into two parts, a non-technical call and a technical interview.

Non-technical video call (30min)

Our first point of contact will be a brief 30 minutes call to get to know each other. We’ll chat about your prior experience and projects, Sipfront’s mission and vision, as well as your expectations to see if there is a potential fit for us to work with you.

Technical interview (2h, video call or on-site)

In this session, we will explore generic Javascript and/or Typescript code snippets together, trying to solve some Advent of Code-Style problems. You’re expected to write code in this session, with our main focus to learn about your technical approach to problems and your communication skills explaining your approach.

We will then together revisit a specific feature which we’ve shipped to production. After a brief high-level explanation of the purpose and architecture, we’ll explore this feature together and talk about how you would plan and implement that yourself. During this discussion, you’re not expected to write code, but reason about technology choices, design and user experience considerations, time estimations and trade-offs.

Decision

We will let you know as soon as possible, typically within a couple of days after the interviews, about our decision.