Senior Backend Software Engineer

Flightradar24 is one of the most successful growth-stage tech companies in Stockholm. Each month more than 50 million aviation enthusiasts visit Flightradar24 (app/website) and our Commercial services team has many of the biggest names in aviation on its customer list. We are looking for a Senior Backend Software Engineer, who can quickly understand existing systems, work independently, and deliver value from day one. You will play a key role in evolving and improving our backend services, working closely with other engineers and stakeholders. The work includes both hands-on development and architectural decision-making. The position requires that you are able to work in Stockholm, Sweden. Relocation is not offered for this role. What you’ll do Your responsibilities include Building backend services for high-volume real-time aircraft telemetry Designing and improving data ingestion, streaming, and event processing (batch and real-time) Refactoring and enhancing existing services, pipelines, and infrastructure Implementing robust data collection, transformation, and storage solutions Operating and improving cloud-based platforms (primarily AWS) Improving observability, reliability, and operational tooling for production systems Contributing to best practices around CI/CD, testing, code quality, and documentation Collaborating with software engineers, data engineers, and analysts to deliver reliable data products Current tech stack Backend services: C++ and Python Cloud & Data Platform: AWS (S3, Glue/Spark, Airflow/MWAA, Athena, MSK/Kafka, Lambda) Streaming & Messaging: Kafka, RabbitMQ Databases & Storage: SQL/NoSQL systems (e.g., MySQL/MariaDB/Postgres, Redis, DynamoDB, Hazelcast) DevOps & Platform: Docker, Kubernetes/EKS, Terraform Engineering practices: Infrastructure as Code, CI/CD, linting, unit tests, integration tests Required technical competence Strong experience with software development in C++, Python, Go, Rust, (or similar) Strong experience designing and operating production backend systems Experience with data engineering architectures for ingestion and transformation Experience working with cloud-based platforms, preferably AWS Solid understanding of databases Experience with event-driven or streaming architectures (Kafka or similar) Strong understanding of reliability, observability, and production operations Who you are Has several years of hands-on experience building and operating production systems Is self-driven and comfortable making technical decisions independently Can quickly understand and work within an existing codebase and architecture Values clean code, testing, automation, and pragmatic engineering practices Communicates clearly and professionally in English Bonus points Experience with Machine Learning concepts and data platforms supporting ML workloads Experience working with high-volume real-time telemetry or tracking data Domain knowledge in aviation data standards (e.g., ADS-B) or similar About Flightradar24 Flightradar24 is the leading flight tracking and aviation data provider, leveraging the world’s largest ADS-B network. Our B2C platform serves millions, while our B2B solutions empower airlines, airports, and aviation stakeholders with essential operational insights. All this is made possible thanks to our globally distributed network of 55,000+ radio receivers that feed real-time aircraft data into the Flightradar24 platform. Over a billion database entries are added each month and we are processing several years of historical data totalling many terabytes. Our proprietary flight tracking data is industry leading and even investigative government agencies from around the world rely on it for aviation accident investigations. Benefits of working at Flightradar24 include: Opportunity to impact a service with millions of end users from all around the world Contribute to the value which Flightradar24 creates both for B2C and B2B but also for humanity. Modern office in the heart of beautiful d