Senior Java Backend Engineer

About Sinch Sinch is pioneering the way the world communicates. More than 150,000 businesses — including Google, Uber, Paypal, Visa, Tinder, and many others — rely on Sinch’s Customer Communications Cloud to power engaging customer experiences through mobile messaging, voice, and email. Whether you need to verify users or craft omnichannel campaigns, Sinch makes it easy. Our AI-infused Super Network, APIs, and applications ensure you can connect with your customers reliably and securely, at every step of their journey. At Sinch we “Dream Big”, “Win Together”, “Keep it simple”, and “Make it Happen”. These values are our foundation! 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. Salary: The annual salary for this position is between 56,800 Euros - 71,000 Euros. Factors which may affect pay within this range may include skills, education, experience, and other qualifications. Nice to Have Experience with modern Frontend frameworks like React. Experience with MongoDB and OpenSearch. Knowledge of message brokers like Kafka and RabbitMQ Our Hiring Process In Sinch, we are committed to following a recruitment process that is fair, objective, consistent, and equal opportunity. Our Talent Acquisition team, together with hiring managers and the rest of the interviewing team, persistently works towards identifying the people that best fit each open job, based on Sinch’ s hiring needs and candidates’ career expectations. We encourage applications from strong candidates with relevant professional backgrounds for this role. Not all applicants will meet all job requirements exactly! Don't let that stop you from considering Sinch for the next step in your career. We are always open to candidates that could bring new insights and perspectives to Sinch! Please send your CV in English language.