Principal Backend Engineer (Java,Spring Boot)

Must-have: At least 8 years of experience in developing web applications Strong experience in Java Web Development Good understanding of SOLID principles, common design patterns and best practices Proficiency in Java and Kotlin for BE (no experience in Kotlin is accepted, as long as you're willing to study Kotlin)  Container-based development (Docker, docker-compose, Kubernetes) experience Ability to write comprehensive and maintainable test code Experience in using, designing, and building GraphQL, Web Service APIs Extensive experience with Spring framework: Spring Boot, Spring Data, Spring Security, Spring Batch, Spring Cloud Knowledge of Domain Driven Development and Onion/Clean Architecture Solid experience with MySQL or PostgreSQL including performance tuning and optimization Agile/Scrum software development experience Experience in improving application security, performance, and operation Experience of leading a project as a team leader, educating team members Strong sense of ownership Nice-to-have: Strong knowledge of security and performance Strong Knowledge of Microservices architecture design and implementation Willingness to learn and build a deep understanding Build and maintain application infrastructure built on AWS Experience in SaaS product company