Full-stack Engineer (backend oriented)

At Telness Tech, they’re right at that Jurassic Park moment when Samuel L. Jackson says, "Hold onto your butts." They’ve built a platform to help telcos ditch those 20th-century legacy systems, and now it’s time to scale from thousands to millions of users without everything blowing up.

We’re looking for a Full Stack Engineer with a Backend soul who isn’t afraid to jump from one language to another. You don’t need to be a Go expert from day one, but you do need that senior mindset to tackle complex problems and feel right at home using AI to be more efficient in your daily workflow.

At Telness Tech, they’re building the technology that allows modern telecom brands to launch, scale, and operate entirely in the cloud. Their platform powers both their own operator and multiple customers across Europe and the US, and as the business grows, the platform needs to remain stable, scalable, and easy for engineers to build on.

This is where you come in...

As a Full Stack Engineer with a strong focus on the Backend, you will play a key role in designing and building core components as the platform scales from thousands to millions of users. You are expected to take deep ownership of your projects, driving technical improvements and solving complex challenges in core domains such as Telecoms and Payments.

While your day-to-day will involve working with a modern event-driven architecture in Go, they are looking for someone who isn't afraid to dive into the React frontend when the product requires it.

As you’re probably tired of reading by now, we’d also like to find a profile with an AI-native mindset that naturally integrates tools like Claude or ChatGPT into their workflow to boost efficiency, always applying engineering judgment with sentidiño to ensure code quality and stability.

• 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.
• Drive technical improvements in workflows and engineering practices to support global growth.

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.

🚀 Learning budget for courses and conferences.

🧑🏾‍⚕️Health insurance

Telness Tech is a company with headquarters in Stockholm 🇸🇪 and a growing footprint in Spain 🇪🇸. As part of their global expansion, they are building a tech presence in Madrid.

For this role, they are looking for someone based in the Madrid region who can join the team in a hybrid setup, spending approximately one day per week in the office and the rest working remotely. However, since they are still in the process of building the Spanish team, you will start 100% remotely until the new Madrid offices are officially opened. You’ll collaborate daily with the Platform team in Sweden and occasionally visit Stockholm for planning sessions or team meetups.

Collaboration is the engine that drives the platform, which is why the team stays synced during a central window. The standard schedule is Monday to Friday, 8:00 to 17:00 CET (including a one-hour lunch break), but you won't find a rigid, "clock-in" culture here.

They believe in genuine flexibility: you can start and finish up to an hour earlier or later (starting between 7:00 and 9:00 CET) to adapt to your personal life. What matters most to them is impact and accountability, not just "desk time". Many team members have school-aged children and often adjust their start times or step away for school runs. As long as you are available for the 9:30 stand-ups and stay aligned with the team, you’ll have the autonomy to manage your own schedule.

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.