Job title: Senior Product Engineer (AI-Native)

Location: Remote (Within Spain)

Contract: Freelance/Contract

We’re searching for a Product Engineer to support in building a multiplatform AI-powered document system, serving hundreds of thousands of users every month.

Key Responsibilities

• Build and maintain the core multiplatform document system, owning features end-to-end from idea to production across React frontends, Node.js/Express backends, and PostgreSQL/Databricks data layers
• Design and orchestrate agentic AI workflows using LangGraph, Claude Agent SDK, and MCP protocols; integrate LLMs into product features via prompt chains, tool calling, and function execution
• Proactively instrument features, measure impact, seek user feedback, and iterate based on what you discover treating metrics as a compass, not a report card
• Build, maintain, and extend automation pipelines connected to AI agents, external APIs, webhooks, and cloud services on GCP
• Contribute to database schema design (PostgreSQL, BigQuery), build and maintain RESTful APIs, and help manage cloud infrastructure on Google Cloud Platform
• Collaborate with engineers, designers, and leadership to shape the product roadmap

Required Experience

• 2–5 years of full-stack experience in a high-output team, with the ability to balance speed and quality
• Deep Python, TypeScript, and React proficiency frontend (Hooks, Context API, Vite, Shadcn UI) and backend (Node.js, Express, REST APIs, PostgreSQL)
• AI-native mindset: you reach for agents by default, understand MCP and agentic orchestration patterns, and have built guardrails to trust them progressively
• Strong UX instincts you can distinguish good from bad UX and share examples to back it up
• Self-driven and business-aware: you care about solving real problems and moving the needle on metrics, not just shipping features

Nice to Have

• Hands on experience with LLMs in production, prompt tuning, RAG pipelines, or vector databases (Pinecone, Weaviate)
• Familiarity with agentic frameworks (LangGraph, CrewAI) and LLM observability tools (Langfuse, LangSmith)
• Experience with GCP and cloud platforms
• A genuine passion for staying on the frontier: new models, protocols (MCP, A2A), and developer tooling

Please apply for more information.