Senior Backend Engineer

Umain AB; Stockholms kommun; Hybrid; SEK 542,299 - 759,219; Full time

Benefits offered by this job

Personal coach

Diverse project opportunities

Collaborative work environment

Job summary

Umain AB in Stockholm is seeking a Senior Backend Engineer to develop robust backend systems in Kotlin, Go, and TypeScript. You will have a significant impact on crucial projects for both local and international clients. Successful candidates will have over 5 years of experience and be able to design and oversee systems end-to-end. The company fosters a collaborative environment with opportunities for growth, mentoring, and working with leading brands worldwide.

Qualifications

• Over 5 years of experience in backend service development.
• Comfortable with system ownership from design to deployment.
• Strong in Kotlin, Go, or TypeScript.
• Experience in code reviews and mentoring peers.
• Thinking about product impact and maintainability.

Responsibilities

• Build high-performance backend systems in required languages.
• Work with frameworks such as Ktor, Fiber, and NestJS.
• Design cloud-native systems with Infrastructure as Code.
• Develop robust data models and database architectures.
• Build observable systems with the right monitoring tools.

Skills

Backend services development

Kotlin

Go

TypeScript

API design

Cloud technologies

CI/CD pipelines

Tools

Terraform

AWS

GCP

Azure

Job description

At Umain, we're not just creating software; we're crafting the future, one innovative project at a time. With our motto "Shape, Ship, Scale," we empower our team to not only envision the future but also play a pivotal role in building it. We're a dynamic team where you can shape the future, ship groundbreaking solutions, and scale your abilities in many different ways.

We are now looking for Senior Backend Engineers who want to build robust solutions that power products used by millions of people.

We have a proven track record:

• 400M+ total app downloads

• 50M+ monthly active users

• Backends handling tens of thousands of requests per second

• Globally recognized, multi-market applications

The office in Stockholm is our default workplace, but we stay flexible when working from home makes sense for the team or the project. We trust each other to coordinate and keep things professional.

Most of our work is built in Kotlin, Go, and TypeScript, and we aim to pick the tools that best fit each project so our teams can focus on delivering the right solution.

The role is broad but centered on backend. You'll work on projects for both Swedish and international companies, including systems that integrate external services, automation, and frontend clients.

As a Senior Backend Developer, your role will involve:

• Building high-performance backend systems in Go, Kotlin, TypeScript (Node.js), or Python, depending on the project.
• Working with frameworks such as Ktor, Fiber, and NestJS.
• Designing cloud-native systems with Infrastructure as Code (Terraform) across AWS, GCP, and Azure.
• Developing robust data models and database architectures to support application requirements.
• Building observable systems with the right metrics, logs, tracing, and alerting to understand and operate what we ship.
• Building and maintaining CI/CD pipelines with containerized deployments and scaling strategies.

If you're excited by working across the stack, always learning, and making a real impact at scale, we believe you'll feel at home at Umain.

Who You Are:

• 5+ years of experience building and running backend services in production.
• Comfortable owning a system end to end, from API design to deployment and operations.
• Strong in at least one of our core languages (Kotlin, Go, or TypeScript), and willing to pick up others as projects demand.
• Experience making technical decisions on a team: weighing tradeoffs, reviewing code, and mentoring peers.
• A product mindset: You think about maintainability, user impact, and long-term health, not just the ticket in front of you.
• Familiar with agentic development tools.
• You treat unfamiliar problems and new technologies as an opportunity rather than a risk. In consulting, the next project often looks nothing like the last one, and you see that as a feature.

What We Offer:

• A personal coach and support to help you develop both professionally and personally.
• A range of diverse projects that explore and push the boundaries of what's possible.
• A fun and fair work environment where you can grow through meaningful challenges and great colleagues.
• Multidisciplinary teams where backend engineers work closely with product, design, analysis, and testing.
• Working alongside some of the largest and most forward-thinking brands on the planet.