Lead AI Engineer
Job Description:
We are looking for an AI Engineer to modernize and enhance our existing regex/keyword-based ElasticSearch system by integrating state-of-the-art semantic search, dense retrieval, and LLM-powered ranking techniques.
This role will drive the transformation of traditional search into an intelligent, context-aware, personalized, and high-precision search experience.
The ideal candidate has hands-on experience with ElasticSearch internals , information retrieval (IR) , embedding-based search , BM25 , re-ranking , LLM-based retrieval pipelines , and AWS cloud deployment.
Roles & Responsibilities
Modernizing the Search Platform
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Analyze limitations in current regex & keyword-only search implementation on ElasticSearch.
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Enhance search relevance using:
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BM25 tuning
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Synonyms, analyzers, custom tokenizers
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Boosting strategies and scoring optimization
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Introduce semantic / vector-based search using dense embeddings.
- LLM-Driven Search & RAG Integration
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Implement LLM-powered search workflows including:
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Query rewriting and expansion
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Embedding generation (OpenAI, Cohere, Sentence Transformers, etc.)
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Hybrid retrieval (BM25 vector search)
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Re-ranking using cross-encoders or LLM evaluators
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Build RAG (Retrieval Augmented Generation) flows using ElasticSearch vectors, OpenSearch, or AWS-native tools.
- Search Infrastructure Engineering
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Build and optimize search APIs for latency, relevance, and throughput.
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Design scalable pipelines for:
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Indexing structured and unstructured text
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Maintaining embedding stores
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Real-time incremental updates
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Implement caching, failover, and search monitoring dashboards.
- AWS Cloud Delivery
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Deploy and operate solutions on AWS, leveraging:
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OpenSearch Service or EC2-managed ElasticSearch
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Lambda, ECS/EKS, API Gateway, SQS/SNS
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SageMaker for embedding generation or re-ranking models
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Implement CI/CD for search models and pipelines.
- Evaluation & Continuous Improvement
- Develop search evaluation metrics (nDCG, MRR, precision@k, recall).
- Conduct A/B experiments to measure improvements.
- Tune ranking functions and hybrid search scoring.
- Partner with product teams to refine search behaviors with real usage patterns.
Required Skills & Qualifications
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5 10 years of experience in AI/ML, NLP, or IR systems, with hands-on search engineering.
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Strong expertise in ElasticSearch/OpenSearch: analyzers, mappings, scoring, BM25, aggregations, vectors.
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Experience with semantic search:
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Embeddings (BERT, SBERT, Llama, GPT-based, Cohere)
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Vector databases or ES vector fields
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Approximate nearest neighbor (ANN) techniques
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Working knowledge of LLM-based retrieval and RAG architectures.
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Proficient in Python; familiarity with Java/Scala is a plus.
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Hands-on AWS experience (OpenSearch, SageMaker, Lambda, ECS/EKS, EC2, S3, IAM).
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Experience building and deploying APIs using FastAPI/Flask and containerizing with Docker.
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Familiar with typical IR metrics and search evaluation frameworks.
Preferred Skills
- Knowledge of cross-encoder and bi-encoder architectures for re-ranking.
- Experience with query understanding, spell correction, autocorrect, and autocomplete features.
- Exposure to LLMOps / MLOps in search use cases.
- Understanding of multi-modal search (text images) is a plus.
- Experience with knowledge graphs or metadata-aware search.