Senior Software Engineer (US Eastern Time)

Telness Tech is here to shake up the telco industry and finally bring it into the digital age. Born in Sweden, they’re already expanding across the US and Europe with Seamless OS, their SaaS platform. In a nutshell, they enable any company — whether a traditional telecom operator or not — to launch fully digital communication services quickly, flexibly, and at scale.

We’re looking for a Senior Software Engineer with a fullstack mindset, a strong backend focus, and an end-to-end approach. Someone with the autonomy to design, build, and evolve features from start to finish, make sound architectural decisions, and help scale a platform that’s expanding into new markets, especially the US.

At Telness Tech, they’re building the technology that enables modern telecom brands to launch, scale, and operate fully in the cloud. Their platform powers both their own mobile operator and multiple customers across Europe and the US. Now, as they accelerate their expansion in the American market, they’re looking to strengthen the team to keep the platform moving and supported during US working hours.

This is where you come in...

As a Senior Software Engineer, with a fullstack profile and a strong Backend focus, you’ll primarily support the US market and team, taking ownership of the development and evolution of the platform during US hours. You’ll work with plenty of autonomy, while staying closely coordinated with the European engineering team so projects can keep moving across both time zones.

A big part of the role will be designing and building core components as the platform scales from thousands to millions of users.

There’s a strong ownership mindset at Telness Tech: engineers are expected to drive their projects forward, contribute to technical improvements, and tackle complex challenges across core domains such as Telecommunications and Payments.

Most of the day-to-day work happens in Go, within a modern event-driven architecture, but this is very much a fullstack environment. Being comfortable jumping into React when the product needs it is definitely part of the deal.

And, as you’re probably tired of reading by now, we’d also love to find someone with an AI-native mindset, naturally integrating tools like Claude or ChatGPT into their workflow to move faster, while applying good engineering judgment to keep the codebase robust and reliable.

• Design and build fundamental components to scale the platform from thousands to hundreds of millions of users.
• Develop high-quality code primarily in Go, maintaining an event-driven architecture.
• Jump into the frontend using React and TypeScript whenever the project or the team requires it.
• Take full ownership of projects, from initial design to final deployment and maintenance.
• Leverage AI tools (like Claude and ChatGPT) to speed up scaffolding, testing, and planning.
• Refine and audit AI-generated code to ensure it meets the high bar of engineering standards.
• Collaborate on DevOps tasks, handling Docker, Kubernetes, and Terraform for GitOps-based deployments.
• Solve complex challenges in multiple domains, preferably in domains like Payments, Billing or Telecom.
• Provide continuity and support for the US team during your working hours, solving technical needs and helping projects keep moving smoothly across time zones.

The engineering culture is built on autonomy and modern practices. You’ll work in a high-trust environment using a Kanban-style methodology where priorities are clear but how you execute is up to your senior judgment. Communication is key, and since the team is international, everything happens in English.

The tech stack is cutting-edge and designed for massive scale

Backend: Your main tool will be Go (Golang), though you might encounter some Python for AI-related tasks.

Architecture: Everything is event-driven, using gRPC for service communication and PostgreSQL with event sourcing for data consistency.

Frontend: A modern setup with React, TypeScript, and TanStack, recently migrated to Vite for lightning-fast development.

Infrastructure & DevOps: It’s a cloud-native world on AWS. You’ll use Kubernetes (even for local dev), Docker, and Terraform. Deployments follow GitOps principles through Argo CD.

Tools: Linear for task planning, Notion for documentation, and Coralogix for observability and tracing. Plus, an AI-first approach using ChatGPT and Cloud Code to boost your daily productivity.

At Telness Tech, you’ll join a company that truly lives by what it builds, a place where technology, trust, and people go hand in hand.

They offer

🌴 30 days of paid vacation per year.

🏠 Remote-first from anywhere in Spain. You’ll only need to travel to Madrid occasionally for team meetups or company events.

🚀 Learning budget for courses and conferences.

🧑🏾‍⚕️Health insurance

Telness Tech is headquartered in Stockholm 🫎 and has a growing presence in Spain 🥘. As part of their global expansion, they’re also building out their tech team in Spain.

For this role, they’re looking for someone based in Spain, but the setup is remote-first, so you can work from anywhere in the country. 🏡

There’s no fixed requirement to go into an office, although you should be open to occasional trips to Madrid when it makes sense to get together with the team or for company events, especially the summer and Christmas parties. There may also be the occasional trip to Stockholm for planning sessions or team meetups.

This role follows a different schedule from the usual one at Telness Tech, and we want to be transparent about it from the start: you’ll work approximately 14:00–22:00 CET, Monday to Friday, with around 30 minutes of flexibility around your start and finish time.

The reason is simple: you’ll primarily be supporting the US team and market, so your working hours need to have a strong overlap with US Eastern Time, while still allowing some coordination with the European team at the beginning of your day.

This schedule is a core part of the role rather than an occasional shift, so afternoon/evening hours will be your regular working pattern. It’s important that this is a schedule you’re comfortable with on a day-to-day basis.

👉 Interested in Telness Tech but this schedule doesn’t work for you? They also have a very similar role open with standard working hours in Spain. In that case, the position is hybrid in Madrid. You can check out all the details here: Telness Tech Full-stack Engineer.

You will be joining the engineering team led by Hantao Wang, Engineering Manager. Hantao is known for his hands-on approach and for fostering an environment of high autonomy and transparency. The team currently consists of six skilled developers who work closely together to tackle the platform's biggest challenges.

Since Telness Tech is a global company, you’ll also collaborate with Product Managers and other engineering chapters across Sweden and Spain. You’ll find a group of people who are not only technically brilliant but also deeply committed to helping each other grow. Whether it's a quick pair-programming session to squash a bug or a high-level architectural discussion about Payments or Telecoms, you'll never feel like you're working in a silo.