We are looking for talented Senior Java Engineer to join our team in Poland. Our California-based customer is an American global e-commerce leader, one of the most popular and successful websites on the Internet. It provides platform services by connecting millions of sellers and buyers in more than 190 markets around the world. The Senior Java Engineer will be a part of the AI Core team to bring new experiences for sellers and buyers leveraging Machine Learning models and other Artificial Intelligence tools to maximize the fun and accuracy of shopping experience. Main Responsibilities: Design, build, and maintain efficient, reusable, and reliable code Suggest technical and functional improvements to add value to the product Conduct design and code reviews to deliver high quality product Minimum Requirements: At least 5 years of proficiency in JAVA or Kotlin technologies Deep experience with the Spring Framework Experience with NoSQL databases (one year at least) Knowledge of different communication protocols such as REST, gRPC, and GraphQL Very good spoken and written knowledge of English language (C1) BSc or MSc in Computer Science, Engineering or relevant field Preferred Requirements An experience with Apache Kafka and its architecture for real-time data streaming Experience with reactive programming (Project Reactor) Experience with Docker for containerization of applications Familiarity with Kubernetes for container orchestration and management Experience with large-scale distributed systems. Professional growth: Strong engineering culture Challenging projects and mature teams Personalized on-demand cross-company mentoring support enabling you to learn new things faster Plenty of opportunities to share knowledge and get more experience such as opportunity to mentor others, speak at events, and contribute to pre-sales Direct communication with the customer An individual education budget A friendly, supportive and dynamic work environment Care, comfort and fun A relocation package Flexible working hours Healthcare & sport benefits Corporate events, outstanding parties and team buildings We offer: Flexible working format - remote, office-based or flexible A competitive salary Personalized career growth Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more) Active tech communities with regular knowledge sharing Education reimbursement Memorable anniversary presents Corporate events and team buildings