Senior Java Backend Engineer

Sinch

Madrid, Spain

Essence of the Role

As a Senior Software Engineer, you will play a key role in designing and building the next generation of our Contacts Platform. You will work in a dynamic, collaborative environment to develop scalable distributed systems. Your contributions will directly impact the efficiency, performance, and safety of conversations at scale.

What You’ll Do

Design, develop, and maintain backend services for Contacts Platform, while contributing to our frontend applications.
Build high-performance, scalable, and distributed systems.
Work with Java, Spring, Kafka, MongoDB, OpenSearch to enhance our product, ensuring safety, efficiency, and responsiveness.
Develop internal tools for monitoring, debugging, and optimizing applications at scale.
Ensure observability, reliability, and fault tolerance across all services.
Collaborate with cross-functional teams including Software Engineers, UX Designers and Product Managers.
Maintain a strong focus on code quality, security, and best practices in software development.

This is a 95% remote role. You must be based in Spain and we will bring you to the office in Madrid for some days every quarter.

Requirements

Production-level experience in backend development using Java.
Deep understanding of distributed systems and experience building high-scale microservices and event-driven architectures.
Strong background in database design and optimization, particularly with MongoDB, Cassandra, or other distributed databases.
Experience with observability, logging, and monitoring tools for debugging and performance analysis.
Familiarity with cloud platforms (AWS, GCP, or Azure) and containerized deployments (Docker, Kubernetes).
A problem-solving mindset with the ability to debug complex distributed systems.
Strong communication skills and the ability to work effectively in a collaborative environment.