
Klein
From Spain (UTC+4)
5 years of commercial experience
Lemon.io stats
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projects done0
hours workedKlein – Python, OpenAI, LLM
Klein is a seasoned AI Engineer with a physics background who transitioned from Machine Learning to AI, specializing in LLM orchestration over the past 2–3 years. As an early contributor to LangChain, he has expertise in RAG pipelines, prompt engineering, embeddings, and agent design.
Klein takes a deep dive into every challenge and takes a holistic approach with a strong focus on safety, observability, and agent guardrails. He excels in fast-paced startup cultures, enjoys contributing to both product and execution, and has experience working with C-levels and scaling a team.
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Let’s get started today!Experience Highlights
Full-stack AI Engineer
It's a specialized speech-to-text SaaS offering fast, accurate transcriptions via custom ASR models for students and researchers.
- Created a full-stack SaaS audio transcription platform using Wasp (Node.js/Prisma) and a dynamic front end using React;
- Integrated third-party services—Google Analytics, Auth0, and Stripe—for user insights, secure authentication, and payment management;
- Created a real-time highlighting system syncing audio with transcript text for smoother editing and interactivity;
- Oversaw the product design process, establishing information architecture, visual design (UI/UX), and user journeys to produce a user-friendly interface;
- Implemented Whisper-small ASR on AWS SageMaker for a fast, cost-effective transcription option in the free tier;
- Carried out data engineering procedures, such as cleaning, transforming, and preparing for AI model training and application use, on proprietary datasets;
- Created an automated post-processing pipeline to improve the grammar, punctuation, and intelligibility of ASR transcripts by utilizing OpenAI's GPT-4o API.
AI Engineer
It's a tool that delivers real-time, context-specific behavioral coaching in Outlook, Teams, Gmail, and Slack to scale company culture.
- Optimized AI pipelines for HR coaching, cutting latency by 62% via prompt tuning, step reduction, and smart caching;
- Reduced infrastructure costs by 30% and boosted accuracy by 20% via efficient token use, strategic caching, and varied AI tools for HR coaching;
- Designed evaluation pipelines and synthetic data workflows to speed up QA and delivery for HR coaching used by 10k+ users per client.
Lead AI Engineer
It's a tool that provides professional-grade AI technology for equity research to the investment banking, hedge fund, asset management, and wealth management industries.
- Designed and implemented an advanced AI pipeline for financial document processing, integrating multi-agent systems, RAG architectures, and prompt engineering techniques, directly contributing to a $5M pre-seed valuation;
- Deployed full-stack AI infrastructure on AWS, scaling from R&D to production-ready MVP;
- Served as Interim CTO for 10 months, scaling the engineering team from 2 to 7 members;
- Developed comprehensive evaluation frameworks with custom benchmarks to measure the performance of agents, prompts, and RAG systems;
- Established quality assurance processes and documentation standards for maintaining technical advantages through research-backed approaches;
- Successfully presented to VCs and prospects, helping secure initial funding and establish early customer relationships;
- Transformed the product into a fully operational GenAI-based financial analysis tool with faster insights, reliable data aggregation, and an intuitive UX.
AI Engineer
It's a personalized AI writing assistant that helps writers organize work, access their library, and receive tailored creative support with AI-powered features.
- Developed a proof-of-concept for a chat-with-your-data copilot to assist writers with personalized content retrieval and creative support;
- Implemented an agent system architecture for specialized writing assistance tasks, including brainstorming, editing, and research;
- Utilized advanced RAG techniques to enhance contextual understanding of user documents and writing style;
- Integrated vector databases for efficient semantic search across personal document libraries and writing collections;
- Leveraged LangChain and LlamaIndex frameworks to build modular, extensible components for document processing and conversation management;
- Designed intelligent prompt engineering workflows to optimize agent responses based on user writing preferences and goals.