Onomondo is on a mission to revolutionize global IoT connectivity. We're here to redefine how connected devices communicate, and we need great engineering leaders to help us push the boundaries of what's possible. Our work directly impacts millions of devices globally, ensuring seamless, low-latency, and highly available connectivity for mission-critical applications. Our services enable secure authentication, signalling, and messaging for devices using Onomondo SIM cards, across 680+ networks in 180+ countries.

We are now hiring for an experienced Software Engineer for our Core Network squad.

The Core Network squad is a cross-functional group of engineers with diverse backgrounds in software engineering, telco systems, embedded engineering, and product management. Together, we are crafting the best cellular network in the world, built for the modern IoT landscape.

What you’ll be doing

As a Software Engineer on the Core Network squad, you’ll be a key contributor to building the infrastructure that powers global IoT connectivity.

You’ll work with a modern tech stack and collaborate with experienced teammates to deliver high-impact features, solving complex engineering challenges at the intersection of software, networking and infrastructure.

This role is a great fit if you’re curious about what happens behind the scenes of connected devices and want to dive into the lower layers of the stack.

Your role will include:

• Design and implement features that interact with our core connectivity infrastructure and that scale with our global footprint

• Write reliable and performant software that helps manage IoT traffic across mobile networks

• Work closely and cross-functionally with peers, gaining exposure to areas like SIM management, cellular protocols, and network orchestration

• Contribute to technical discussions and help us make pragmatic architecture decisions

• Collaborate with engineers across disciplines, bridging the gap between cloud and core network infrastructure

• Help improve our tools, processes and practices in order to bring visibility and control to complex systems, so we can move more confidently as a team

What you’ll bring:

We’re looking for someone who’s curious, capable and eager to grow in a high-performing, collaborative team. You're the kind of engineer who likes to understand how systems really work. You might have explored networking, OS concepts or embedded systems out of curiosity (or in a past job). You write clean code, but are equally interested in what’s happening underneath it.

Technical skills:

• Strong background in building scalable, highly available systems

• You’re comfortable in Go or Node.js, but what excites you is the interplay between code and the systems it runs on

• You’ve worked with cloud infrastructure (such as AWS) and understand how services interact behind the scenes

Ideally:

• Telecom experience would be ideal. Knowledge of telecom protocols, standards, and technologies such as DIAMETER, SS7, and GTP - or core elements such as HLR/HSS, STP, DRA/DEA, MME and PGW

Approach:

• You have a keen interest in protocols and networking, even if you’re not an expert (yet)

• You value teamwork and open communication, and enjoy collaborating with people across disciplines

• You enjoy collaborating with others who think deeply about systems, and you’re eager to keep growing technically

Location:

• Based in Copenhagen. You should be currently based in/around the Copenhagen area today (commutable distance to our office on Islands Brygge)

Why join Onomondo?

The technical playground: We're not exaggerating when we say you'll work on stuff that's genuinely interesting. Running telecom workloads on Kubernetes? Check. Building SoftSIMs that run in software? Check. Enabling global IoT connectivity at scale? Check. This isn't your typical CRUD app on AWS—it's technical challenges that have lots of room for innovation

The culture:

• A playful, ambitious environment where tinkering is encouraged and curiosity is rewarded

• A diverse team where your fingerprints will be on everything we build

• Trust and autonomy—we hire smart people and let them do smart things

• A 2000 sqm HQ in Islands Brygge that's one-of-a-kind in design and energy
  

The perks:

• Competitive salary and warrants

• Five weeks of vacation and great healthcare

• Legendary catered lunches, snack heaven, and drinks

• Flexible work—HQ or home when you need focus time

• Time to exercise during work hours

• Most importantly: lovely colleagues who genuinely enjoy spending time together
  

The tech stack: Node.js, Go, Kubernetes, Terraform, Ansible, AWS, Prometheus, Grafana, ArgoCD, and GitHub Actions

Our hiring process

We care deeply about creating a fair and inclusive process. That means:

• We don't need your picture or cover letter—just your CV

• We select candidates based on skills and relevant experience

• We're fast but thoughtful—you'll feel informed, respected, and excited throughout

The stages:

1. 30-minute screening call with our recruiter, Christian Payne

2. Technical interview (1hr) with an Engineering Manager and a Staff Engineer

3. Culture Interview (1hr) with Henrik, our CTO/co-founder

4. Meet the team (1hr)
   

Ready to make an impact?

If you're the kind of person who gets excited about diving into technical problems, enjoys mentoring curious engineers, and wants to lead a team building genuinely cool infrastructure, let's talk.

Note: We review and interview candidates continually, so we encourage you to apply at your earliest convenience.

Learn more about us and other opportunities at onomondo.com/careers