Senior AI Engineer (m / w / d) - RAG & Search Optimization

freelance.ca; Walldorf; Remote; EUR 40.000 - 60.000; Vollzeit

Zusammenfassung

A freelance platform is seeking an experienced Senior AI Engineer to optimize retrieval systems and enhance search performance. This full-time remote position requires expertise in JavaScript/TypeScript, OpenSearch, and AI fundamentals. The role involves building evaluation frameworks and improving document ingestion processes, starting on 06.10.2025 until 31.12.2025.

Qualifikationen

• Proven experience building and maintaining production systems with NestJS.
• Hands-on experience building or optimizing RAG pipelines.
• Strong practical knowledge of OpenSearch or Elasticsearch.
• Solid grasp of core AI concepts, particularly in NLP.
• Thrive in a fast-paced environment, take initiative.

Aufgaben

• Optimize the Retriever and fine-tune similarity search.
• Design and implement a testing suite for conversational search.
• Curate high-quality test datasets to benchmark retriever performance.
• Analyze and improve the document ingestion process.
• Work proactively to identify improvement opportunities.

Kenntnisse

Expert-Level JavaScript / TypeScript

RAG & Search Experience

OpenSearch Proficiency

AI / ML Fundamentals

Pragmatic & Proactive Mindset

Jobbeschreibung

Overview

Senior AI Engineer (m / w / d) - RAG & Search Optimization - Freelance

Responsibilities

• Optimize the Retriever: Dive deep into our multi-step retriever, fine-tuning the interplay between Reciprocal Rank Fusion (RRF) for similarity search and BM25 for keyword relevance in OpenSearch.
• Build an Evaluation Framework: Design and implement a robust testing suite for our conversational search from the ground up. Your framework will be the source of truth for measuring precision, recall, and other key relevance metrics.
• Develop Test Data: Curate and create high-quality, domain-specific test datasets to rigorously benchmark and validate retriever performance.
• Enhance the Ingestion Pipeline: Analyze and improve our complex document ingestion process to ensure data is indexed effectively for optimal retrieval.
• Collaborate and Innovate: Work in a dynamic environment, responding to ad-hoc requests and proactively identifying opportunities to improve our system, potentially by introducing advanced techniques like rerankers.

Qualifications

• Expert-Level JavaScript / TypeScript: Proven experience building and maintaining production systems with NestJS.
• RAG & Search Experience: Demonstrable, hands-on experience building or optimizing RAG pipelines. You must be comfortable with the theory and practice of hybrid search.
• OpenSearch Proficiency: Strong practical knowledge of OpenSearch (or Elasticsearch), including query DSL, indexing strategies, and performance tuning for search relevance.
• AI / ML Fundamentals: A solid grasp of core AI concepts, particularly in NLP, vector embeddings, and search evaluation metrics (precision, recall, etc.).
• Pragmatic & Proactive Mindset: You thrive in a fast-paced environment, are comfortable with ambiguity, and can take initiative to build solutions from scratch.
• Nice to have:
• Hands-on experience with AI orchestration frameworks like LangGraph.
• Familiarity with advanced retrieval techniques, such as implementing rerankers (e.g. cross-encoders).
• Direct experience with BM25 and fusion methods like RRF.

Details

• Location: remote
• Start: 06.10.2025
• Duration: till 31.12.2025
• Workload: Full-Time (200 Hours)
• Language: English