Senior Software Engineer (Java) - Gen AI

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!

As a Senior Software Engineer, you will play a key role in designing and building the next generation of our AI-powered chatbot platform. You will work in a dynamic, collaborative environment to develop scalable distributed systems that power real-time messaging and LLM-based applications. Your contributions will directly impact the efficiency, performance, and safety of AI-driven conversations at scale.

What You’ll Do

• Design, develop, and maintain backend services for AI-driven chatbot orchestration.
• Build high-performance, scalable, and distributed systems for real-time messaging and workflow execution.
• Work with LLMs (Large Language Models) to enhance bot interactions, ensuring safety, efficiency, and responsiveness.
• Develop internal tools for monitoring, debugging, and optimizing LLM-based applications at scale.
• Implement and optimize workflow orchestration using frameworks like Temporal.io.
• Ensure observability, reliability, and fault tolerance across all services.
• Collaborate with cross-functional teams including ML engineers, frontend engineers, 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

What We Look For

• Production-level experience in backend development using Java and Typescript
• 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.

Nice to Have

• Experience with LLM fine-tuning or AI-driven chatbot development.
• Knowledge of message brokers like Kafka, RabbitMQ,
• Hands-on experience with Temporal.io or similar workflow orchestration frameworks.

Benefits

Sinch is a global company composed of people from different countries and cultures. Our benefits adjust regionally to support employees and help them to thrive in every stage of life. We offer valuable benefits and resources, including health and life insurance, a flexible work environment, retirement savings plans, and more.

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!