Summary: Seeking a Senior Java Developer with OpenSearch/ES expertise to implement advanced conversational search solutions and optimize large-scale search systems in AWS. Highlights: 1. Implement advanced solutions for conversational search 2. Develop and maintain backend services supporting search functionality 3. Contribute to design decisions and system architecture We're looking for a mature **Senior Java Developer** who is OpenSearch or ES SME, has solid experience with vector/hybrid search and can operate large\-scale search systems in AWS. This role focuses on implementing advanced solutions to support conversational search for our client. You will be part of a team that values innovation and technical excellence. **Responsibilities** * Collaborate with cross\-functional teams to deliver scalable search solutions * Participate in system architecture discussions and contribute to design decisions * Develop and maintain backend services supporting search functionality * Optimize search performance for high\-volume environments * Integrate new search features and enhancements based on business requirements * Monitor system health and troubleshoot issues in production * Document technical processes and maintain clear code standards * Support continuous improvement by evaluating emerging technologies * Provide technical guidance and mentorship to team members **Requirements** * Minimum 3 years of experience as a Java Developer * Extensive hands\-on experience with AWS OpenSearch or Elasticsearch in production environments * Strong knowledge of search relevance and ranking algorithms such as BM25, boosting, and rescoring * Practical experience with vector search and semantic search methods including k\-NN, ANN, and embeddings * Ability to design and optimize hybrid search systems combining lexical and vector approaches * Advanced Java skills with experience in developing or extending OpenSearch/Elasticsearch plugins * Experience building search solutions tailored to collections or tenants * Proven ability to tune search relevance using metrics like precision, recall, and NDCG * Expertise in distributed systems and performance optimization * English proficiency at B2\+ level or higher, both written and spoken **Nice to have** * Experience with search evaluation techniques and A/B testing for measuring improvements * Background in knowledge discovery or enterprise search projects * Familiarity with OpenSearch plugin technology and related concepts