Software Engineer - Java API developer

We are seeking a highly skilled Senior Java API developer with experience in building high-performing, scalable, enterprise-grade backend systems in the digital advertising domain. In this role, you will design, develop, and optimize backend services powering Mobile Ad SDK systems and AI-driven products such as recommendation engines, monetization optimization platforms, and intelligent ad delivery systems. This role will be responsible for productionizing machine learning models, building high-performance APIs, and enabling intelligent decision systems at scale

What You’ll Do:

• Design and develop scalable, secure, and high-performance RESTful APIs using Java (Java 11+) and Spring Boot.
• Own end-to-end solution design, planning, execution, and release of backend features.
• Build and maintain backend services supporting AI-driven initiatives (recommendation systems, predictive analytics).
• Productionize and integrate ML models into backend systems, enabling real-time intelligent decisioning.
• Develop efficient data models and optimize database queries (MySQL/PostgreSQL) for performance and reliability.
• Ensure API security using OAuth2, JWT, and role-based access controls.
• Build for scale-design systems capable of handling high concurrency, large data volumes, and low-latency requirements.
• Implement observability best practices including logging, monitoring, tracing, and alerting.
• Participate in code reviews, design discussions, and technical decision-making to ensure engineering excellence.
• Collaborate cross-functionally with Analytics, Product, SDK, UI, Ad server, DevOps, and QA teams to deliver AI-powered features.
• Leverage generative AI tools and advanced prompt engineering techniques to enhance productivity and code quality.

• 3-6 years of experience in Java development in Linux/UNIX environments.
• Strong proficiency in Core Java, OOPS, Data Structures, and J2EE technologies.
• Hands-on experience with Spring, Spring Boot, and Hibernate.
• Strong experience in REST Web Services development and microservices architecture.
• Proficiency in SQL, schema design, indexing, performance tuning, and complex queries.
• Experience with Docker, Kubernetes, Jenkins, Maven, Git, and CI/CD pipelines.
• Experience working on high-performance and scalable AdTech systems (preferred).
• Working knowledge of Python and integration with AI/ML services.
• Understanding of advanced AI concepts including RAG, agentic AI, model fine-tuning, and recommendation systems.
• Experience in JUnit, TDD, refactoring, and Agile development practices.
• Demonstrated ability to work independently and drive technical ownership., Should have a bachelor’s degree in engineering or an equivalent degree from a well-known institute/university.

Return to Office: PubMatic employees throughout the globe have returned to our offices via a hybrid work schedule (3 days “in office” and 2 days “working remotely”) that is intended to maximize collaboration, innovation, and productivity among teams and across functions.

Benefits: Our benefits package includes the best of what leading organizations provide, such as paternity/maternity leave, healthcare insurance, broadband reimbursement. As well, when we’re back in the office, we all benefit from a kitchen loaded with healthy snacks and drinks and catered lunches and much more!.

Diversity and Inclusion: PubMatic is proud to be an equal opportunity employer; we don’t just value diversity, we promote and celebrate it. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status

About PubMatic

PubMatic is one of the world’s leading scaled digital advertising platforms, offering more transparent advertising solutions to publishers, media buyers, commerce companies and data owners, allowing them to harness the power and potential of the open internet to drive better business outcomes.

Founded in 2006 with the vision that data-driven decisioning would be the future of digital advertising, we enable content creators to run a more profitable advertising business, which in turn allows them to invest back into the multi-screen and multi-format content that consumers demand.