Java Software Engineer

We are looking for a Senior Java Software Engineer - Performance & Scalability to join our team and contribute to the development, optimization and continuous improvement of high-performance, mission-critical software systems within the Gaming Industry.

In this role, you will combine strong Java engineering expertise with a deep understanding of performance optimization, scalability and distributed architectures. You will work on complex, high-traffic gaming environments, helping ensure reliability and stability under heavy workloads while contributing to architectural improvements and technical excellence.

Code.Hub is a leading Tech Recruitment, Learning & Development, Extended Team and Project Delivery partner in Greece. Since 2017, Code.Hub has been helping organizations build and scale high-performing technology teams, while supporting Software Engineers in developing their skills and growing their careers.

With expertise across modern technologies and digital transformation projects, Code.Hub collaborates with leading organizations in FinTech, Banking, Insurance, Gaming, Telecommunications and Consulting, providing services and solutions in technology, consulting, software delivery and operations.

Code.Hub has built one of the strongest tech ecosystems in Greece, managing large-scale technology projects and supporting companies through specialized recruitment and upskilling solutions. In 2026, Code.Hub was certified as a Great Place to Work ®, while also receiving HR Awards distinctions for Talent Management, Recruitment Strategy, Mentoring and Learning & Development initiatives, highlighting the company’s strong investment in people growth, innovation and employee experience.

Our Gaming project sits at the intersection of technology, performance and scale, powering high-traffic, mission-critical systems in one of the most dynamic digital industries. It offers the opportunity to work on complex engineering challenges where scalability, reliability and performance are at the heart of the technology.

Key Responsibilities

• Leading analysis, design, development and optimization initiatives across enterprise-level applications.
• Identifying performance bottlenecks and implementing solutions to improve system scalability, efficiency and reliability.
• Ensuring application performance and stability under high-load and mission-critical conditions.
• Contributing to architectural improvements, modernization initiatives and technical debt reduction.
• Optimizing distributed systems, microservices and event-driven architectures.
• Performing JVM tuning, system profiling and database optimization.
• Supporting deployment processes, monitoring application health and contributing to ongoing system stability.
• Collaborating closely with engineering, architecture, DevOps and other technical teams to deliver robust and scalable solutions.

Required Qualifications

• Strong professional experience in enterprise-level Java development.

  Strong hands-on expertise with Java, Spring Boot, Hibernate, JPA and JavaEE/JakartaEE.

• Proven experience in performance optimization, performance tuning and scalability improvements within distributed systems.
• Hands-on experience with Kubernetes, Docker and containerized environments.
• Solid knowledge of Oracle SQL optimization, query performance and database tuning.
• Strong experience with JVM tuning, profiling and troubleshooting.
• Experience designing and working with microservices and event-driven architectures.
• Experience with messaging technologies such as RabbitMQ.
• Familiarity with monitoring and observability tools such as Grafana and ELK Stack.
• Experience with load and performance testing tools such as JMeter or Gatling.
• Strong understanding of REST APIs, OAuth2/OIDC and system integration patterns.
• Ability to work effectively with high-load, highly available and mission-critical systems.
• Strong analytical and problem-solving capabilities.
• Excellent communication, collaboration and stakeholder-management skills.

Tech Stack

• Java | Spring Boot | Hibernate | JPA | JavaEE/JakartaEE | Microservices | Kubernetes | Docker | Oracle SQL | RabbitMQ | REST APIs | OAuth2/OIDC | Grafana | ELK | JMeter | Gatling | JVM Profiling & Tuning

Nice-to-Have Skills

• Experience working in Gaming or other high-traffic digital environments.
• Exposure to application modernization and technical debt reduction initiatives.
• Experience collaborating with Architecture and DevOps teams on performance-related improvements.
• Familiarity with enterprise-scale, mission-critical application environments.
• Experience contributing to system architecture and scalability improvements.

Let’s Talk About Us

• Hybrid working model.
• Signing Bonus.
• Brand new equipment.
• Exciting & friendly work environment.
• Career & competencies’ development.
• Continuous learning & development experience based on infinity model through Code.Hub’s Code.Learn.
• L&D plan for your career improvement.
• A truly open, inclusive, and competitive-free environment to grow your skills and have fun!
• Internal competitions & rewards.

Let’s Talk About Code.Hub-ers

• You are eligible to free LinkedIn trainings.
• You are eligible to have free pass to all training Code.Learn activities after 6 months from your induction.
• Training & Tech Mentor for your induction.
• Unlimited access to LinkedIn Learning platform (1st semester).
• Sponsoring of a Bachelor and/or Master’s Degree from Athens Tech College.
• Private Health Insurance.
• Performance planning each six months and each two years planning of promotion.
• Cocktail Fridays @ our offices.
• Referral Bonus.