Senior Java Developer İş İlanı

Location: Ankara, Türkiye Employment Type: Full-time (On-site) About Us At SiMTEK Simulation Technologies, we develop advanced software solutions for the defense, aviation, and critical infrastructure sectors. Our expertise spans Artificial Intelligence, Data Analytics, Digital Twin, Simulation, VR/AR, and Training Technologies, delivering innovative solutions for both national and international projects. We are looking for an experienced Senior Java Developer who is passionate about building high-performance, scalable, and mission-critical software systems and wants to be part of our strong engineering culture. Responsibilities Design, develop, test, maintain, and enhance enterprise-grade and mission-critical Java applications. Develop and improve microservice-based applications using Spring Boot. Design and implement secure, scalable, and high-performance RESTful APIs. Develop real-time data processing, messaging, and system integration solutions. Contribute to software architecture design and technical decision-making processes. Develop maintainable, readable, and testable software by applying Clean Code principles, SOLID principles, and design patterns. Participate actively in code reviews and contribute to maintaining high software quality standards. Perform refactoring activities to reduce technical debt and improve existing codebases. Analyze and optimize application performance and troubleshoot complex issues. Contribute to CI/CD pipelines and participate throughout the entire software development lifecycle. Collaborate closely with Front-End, DevOps, QA, and Data Engineering teams. Prepare technical documentation and contribute to the definition of software development standards. Qualifications Bachelor's degree in Computer Engineering, Software Engineering, or a related field. Required Turkish citizenship. Minimum 5 years of professional experience in Java software development. Strong experience with Java 21 (LTS) or later . Solid understanding of modern Java features, including: Virtual Threads (Project Loom) Records Sealed Classes Pattern Matching Streams API Functional Programming Concurrency and Multithreading Hands-on experience with Spring Boot 4.x , Spring Framework 7 , Spring Security , and Spring Data JPA . Experience implementing authentication and authorization using OAuth2, OpenID Connect, and JWT. Experience working with relational databases such as PostgreSQL or Microsoft SQL Server. Strong knowledge of SQL optimization, indexing, transaction management, and database design. Experience with Hibernate/JPA. Experience with messaging platforms such as Kafka, RabbitMQ, or ActiveMQ. Experience with Docker and Kubernetes. Proficiency with Maven or Gradle. Experience using Git and Gitea workflows. Experience developing in Linux environments. Experience writing Unit and Integration Tests. Familiarity with SonarQube, SAST, and secure software development practices. Strong understanding of Clean Code, SOLID principles, Object-Oriented Design (OOD), and GoF Design Patterns. Proven experience in refactoring and improving existing codebases. Passion for writing clean, maintainable, and high-quality code. Experience working in Agile/Scrum environments. Strong analytical thinking and problem-solving skills. Good command of written and spoken English.