C/C++ Engineer

1oT is aggregating many telecoms around the world into one eSIM and connectivity management platform to provide global connectivity to IoT devices. Our two software elements, the eSIM infrastructure and connectivity management platform, have been developed in-house and have stood out in the market. With the certified eSIM infrastructure (1oT eSIM Core), our customers can swap telecoms whenever they wish, and with the connectivity management platform (1oT Terminal), they can control and manage connectivity on a self-service basis either through our UI or APIs. 


Our 2G, 3G, 4G, NB-IoT, and LTE-M connectivity service is used by 4 million IoT devices in 173 countries. But we haven’t stopped there. We have been building our own packet gateway—a secure interface between mobile networks and external packet data networks, including the Internet, private corporate networks, and other IP-based services. You'll be working on the core of 1oT’s connectivity infrastructure. Your job is to ensure seamless, lightning-fast data flow for IoT devices worldwide by building and optimizing our in-house packet router.


This is an on-site position based in Tartu/Tallinn, Estonia. We do not offer relocation assistance.

Number of vacancies

1

Deadline for applying

01.05.2026

Job location

Tallinn/Tartu

Work assignments

What you'll do:

  • Building and improving our in-house router logic to handle global traffic with minimal latency.
  • Developing internal tools for packet inspection, traffic shaping, and network diagnostics that keep our services ahead of the curve.
  • Diving deep into the network stack to squeeze out every bit of performance while maintaining 24/7 stability.
  • Collaborating closely with our infrastructure and development teams to ensure our routing solutions integrate perfectly with our global connectivity platform.
  • Testing, benchmarking, and refining our tools to handle the evolving needs of modern IoT deployments.

Personal qualities

You’re a good fit if:

  • You have at least 3 years of experience in C/C++.
  • You love low-level programming and aren’t afraid of going deep into the specifics of an issue. You take pride in writing efficient, memory-safe, and production-ready code.
  • You are quick to identify bottlenecks, happy to debug complex issues, and ready to iterate until the solution is rock-solid.
  • You believe in readable and maintainable code and thorough documentation.

Language skills

English

Additional requirements

Nice to have:

  • Experience with Linux kernel networking.
  • Knowledge of VPN technologies.
  • Familiarity with containerization Docker and CI/CD pipelines for system-level software.

Company/organization offers

What we offer:

  • Meaningful impact – our connectivity helps track endangered species, deliver vaccines safely, and power off-grid communities
  • Room to grow – we’re a scaling startup with a strong track record and global reach
  • A sharp, no-nonsense team – we value learning, speed, and getting things done
Information Technology
  • Work time: Full time work
  • Workload: 1
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