Senior Backend Engineer

At Umain we're crafting the future, one innovative project at a time. With our motto "Shape, Ship, Scale," we empower our team to envision the future and 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 Gothenburg 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, and scalable systems in modern stacks that suit the project. 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. Why Umain? Career Framework We believe in fairness and clarity, which is why we've established a transparent career framework to ensure equal pay and equal opportunities for all. Your growth and success are as important to us as they are to you. Together with your coach, you will build your own development plan and grow in your career. Work-Life Balance At Umain, we understand that life doesn't pause when you walk into the office. We welcome team members from all walks of life and recognize the richness that different backgrounds, ages, and life stages bring to a team. Whether you're taking care of your family, your pets, or yourself, we're committed to supporting a healthy balance that respects your needs. Skills Over Degrees We're more interested in what you can do than in the diplomas you hold. Talent, drive, and creativity are what count at Umain. Here, you'll find opportunities to grow, learn, and excel in your career, regardless of your educational background. Background check Umain conducts a background check for final candidates in accordance with our internal policies. The check is carried out only with your consent and is ordered by our CISO through our approved screening partner. The scope of the check depends on the role level. This step is performed late in the recruitment process and is used solely to support a secure and fact-based hiring decision.

You will play a key role in designing, developing, and validating our backend system. You will work closely with our software and firmware teams to develop reliable, scalable backend services with a strong focus on quality, testing, and automation. Your experience in backend development and test engineering will be important in shaping and improving our platform. What you will do: Design, develop, and maintain backend services and systems using Go and the Twelve-Factor App methodology. Design, develop, and maintain automated test frameworks, test environments, and validation processes for backend systems and services. Define and implement test strategies covering functionality, integration, system, regression, and performance testing. Build tools and test harnesses to verify the reliability, scalability, and correctness of distributed systems. Optimize software for performance, efficiency, reliability, and scalability. Troubleshoot, debug, and analyze applications and test results to ensure smooth functionality. Collaborate with front-end developers, firmware engineers, and other stakeholders to deliver high-quality software solutions. Participate in code reviews and provide constructive feedback to team members. Your Profile Minimum of 5 years of experience in backend development, test engineering, or a similar role. Experience with Go is a strong advantage. We also welcome candidates with solid backend experience in other typed backend languages. Experience designing and implementing CI-based test execution for backend systems and distributed applications. Experience and familiarity with concurrent and asynchronous programming. Proven experience with RESTful API design, implementation, and testing. Strong familiarity with Linux-based IT systems and test or hosting environments. Knowledge of databases (PostgreSQL, Cassandra) and expertise with in-memory caching solutions (Redis or comparable). Experience with distributed event-streaming and messaging systems, such as Apache Kafka or NATS. Experience working with version control systems (Git) in collaborative environments. Excellent problem-solving skills and attention to detail, with the ability to make sound trade-offs based on business needs and technical requirements. Ability to work independently and as part of a team. You communicate clearly and are comfortable supporting and mentoring less experienced developers. Strong communication skills in English, written and spoken. Proficiency in Swedish is a plus.