Java Spring Boot Backend

I need an experienced Java developer to take full ownership of the backend layer for a rapidly-growing application. The stack is Spring Boot with JPA / Hibernate, running against a PostgreSQL database, and every feature you build must expose clean, well-documented REST endpoints... (Budget: $250 - $750 USD, Jobs: Hibernate, J2EE, Java, JSP, MySQL, PostgreSQL, RESTful API, Spring Boot)