Senior Data Scientist / LLM Developer

About the Position

Senior Data Scientist / LLM Developer

We are seeking a highly skilled Senior Data Scientist / LLM Developer for a contract role with a fintech SaaS company. This role focuses on quantitative research and large language model (LLM) development.

Responsibilities

• Lead quantitative research at a fintech SaaS platform serving crypto, commodities, futures, options, and bilateral trade markets.
• Develop recommender systems and AI-driven tools for risk management and trading analytics.
• Build robust LLM-based applications using industry-standard frameworks and tooling.
• Apply large language models to pharmaceutical workflows to accelerate drug development.

Requirements

• 5+ years of commercial Python experience
• 1+ year of production LLM application development
• Strong proficiency with at least one LLM SDK / framework (OpenAI, Anthropic, Google Gemini, LangChain, LangGraph, Llama Index)
• Production experience with at least one vector database (Pinecone, FAISS, pgvector, Weaviate, Qdrant, Chroma)
• Strong RAG pipeline design experience (chunking strategy, retrieval optimization, reranking, hybrid search)
• A specialization claim helps: RAG architecture, agentic systems, fine-tuning (LoRA / QLoRA), real-time voice AI, on-device inference, or evaluation/observability infrastructure
• Production deployment experience (FastAPI + Modal / AWS Lambda / Vertex AI / Bedrock)
• Strong evaluation + observability mindset (Phoenix, LangSmith, Helicone, custom eval harnesses)
• Comfortable working async with US/EU teams
• English: Upper-Intermediate or higher
• Available for 20+ hours/week - part-time and full-time both supported

We Offer

• Competitive salary: $20-$50/hour
• Flexible working hours: part-time and full-time options available
• Opportunity to work on cutting-edge AI projects
• Direct collaboration with decision-makers
• No re-vetting per project - ever

About the Company

Lemon.io is a developer talent marketplace connecting LLM Developers with funded AI product companies and SMBs for remote contract roles. Developers pass vetting once (5 days average) and get continuous access to a pipeline of pre-vetted projects. Lemon.io rejects 60% of applying companies based on funding stability, product clarity, technical specs, and engineering culture.

Apply to Get Matched

Fill out a quick profile with your stack, rate, availability, and preferences. Prove your skills with a soft skills interview and a technical assessment with senior engineers. Start building and get matched with clients that fit your criteria.