Senior Java Developer – Spring Boot & Monolith

About the role

We are looking for a Senior Java Developer to lead the design, development, and maintenance of large monolithic production systems. You will own architectural decisions, ensure high performance, and mentor the development team.

Key responsibilities

• Design and develop monolithic applications using Spring Boot and the broader Spring ecosystem.
• Implement complex authentication and authorization schemes with Spring Security, OAuth2, JWT, and SSO.
• Build and maintain REST APIs, handling both synchronous and asynchronous integrations.
• Design database schemas, indexes, and complex transactions; optimise heavy queries and batch operations.
• Introduce caching, session management, and synchronization with Redis.
• Manage database schema evolution with Liquibase and ensure backward‑compatible API versioning.
• Define and enforce a modular monolith architecture (package‑by‑feature, bounded contexts).
• Write and maintain high‑coverage unit, integration, and end‑to‑end tests.
• Participate in code reviews, mentor junior developers, and plan refactoring initiatives.

Required profile

• 5+ years of commercial Java development experience.
• Deep understanding of Java 17+, JVM internals, memory management, GC, threading and profiling.
• Proven experience with large monolithic systems and performance optimisation.
• Strong knowledge of relational databases and SQL.
• Ability to make architectural decisions and communicate their business value.

Required skills

• Java 17
• Spring Boot, Spring Framework, Spring MVC
• Spring Security (OAuth2, JWT, SSO)
• Spring Data JPA, Hibernate
• Relational databases (SQL)
• Redis (caching, sessions, synchronization)
• REST API development
• Liquibase
• Maven, Gitlab CI/CD
• Unit, integration and end‑to‑end testing
• Performance profiling and optimisation
• Multithreading, Java Collections, Streams
• Design patterns (SOLID, DRY, KISS)
• HTTP, CORS, WebSockets