Senior Software Development Engineer (Java + React)

Company: Lightning Staff
Location: Remote
Employment: Full-time, B2B

About the Role

Lightning Staff is looking for an experienced Senior Java Developer for potential collaboration on international enterprise projects.

We are interested in engineers who can take ownership of backend development, work with complex integrations, optimize application performance, and contribute to frontend development when needed.

Requirements

• 5+ years of commercial experience with Java
• Strong knowledge of Java 11/17, Spring Framework and Spring Boot
• Experience with microservices architecture and REST APIs
• Hands-on experience with Oracle Database and SQL
• Good understanding of JVM internals, garbage collection and memory management
• Experience with performance profiling, heap dumps and application optimization
• Practical experience with React
• Strong unit testing skills (JUnit, Mockito)
• Experience with Git, Docker and CI/CD
• English: Upper-Intermediate (B2) or higher
• Ability to work independently and take ownership of technical tasks

Nice to Have

• Experience with high-load enterprise applications
• Kafka or RabbitMQ
• Kubernetes
• Monitoring tools (Prometheus, Grafana)
• Java Flight Recorder (JFR)

Responsibilities

• Develop and maintain Java/Spring Boot applications
• Design and implement REST APIs and integrations
• Investigate performance bottlenecks and optimize JVM applications
• Write unit tests and maintain code quality
• Contribute to React-based UI components when required
• Participate in architecture discussions and code reviews
• Collaborate with international engineering teams

What We Offer

• Remote collaboration
• B2B contract
• Opportunities to work on international projects
• Flexible working arrangements depending on the project
• Technical challenges and professional growth