Is this you? Titan Operating System S.L. (Titan OS), the Barcelona-based technology, entertainment, and advertising company, is looking for you! At TitanOS, we live by three core values: Make things happen – We take ownership, move fast, and deliver impact. No ego – We collaborate with respect and humility to reach shared goals. Show genuine passion – We love what we do and never stop learning. Culture and environment are at the heart of our ethos. If the above resonates with you, keep reading because we believe you could be a perfect addition to our incredible team! Role overview: We are looking for a Senior Backend Engineer (Ruby on Rails Developer) with a deep understanding of server-side technologies and a passion for building highly scalable systems that power industry-leading applications. You will be responsible for designing, developing, and maintaining the backend infrastructure that drives our products and services, ensuring they are secure, reliable, and performant. You’ll be instrumental in architecting and delivering robust solutions that power the core functionality of our business. This role is for someone who thrives on solving complex problems and is driven by the desire to contribute to a high-impact product every day. Key responsibilities Designing and developing highly scalable backend services and APIs to support front-end applications and third-party integrations. Building and maintaining databases, ensuring data is stored securely and can be accessed efficiently. Collaborating with front-end developers, DevOps, and product teams to define and implement new features. Optimising the performance and reliability of server-side code to ensure seamless user experiences. Ensuring the security of backend systems through the implementation of best practices and security protocols. Writing clean, maintainable, and well-documented code, adhering to industry standards and team best practices. Monitoring and troubleshooting production systems, ensuring high availability and rapid response to issues. Participating in code reviews and contributing to the continuous improvement of development processes. Requirements What makes you a great fit: +7 years of professional experience as a Backend Engineer, working on large-scale systems. Proficiency in Ruby on Rails. Strong knowledge of database systems (SQL and NoSQL), with experience in designing efficient data architectures. Experience with cloud platforms like AWS, GCP, or Azure, and familiarity with containerization tools like Docker and Kubernetes. Solid understanding of RESTful API design and development, including experience integrating third-party services. A strong focus on performance optimization, scalability, and security. Excellent problem-solving skills and attention to detail. A Bachelor’s degree in Computer Science, Software Engineering, or a related field is preferred but not required. Strong communicator and fluent in English Benefits Reasons to apply: Competitive compensation Private health insurance Friendly, diverse, and international work environment Opportunity to work outside of your comfort zone and develop professionally in an exciting and fast-growing CTV industry. Change the future of TV! A unique opportunity to join a well-funded, high-growth company in the early stages to help shape a product/business that will impact millions. If you're excited about this position, don’t hesitate to apply. We’re waiting for you to join us! And if you want to know more about us, follow us on LinkedIn !