based patent search and software company founded by veterans of the professional patent search industry. Our team of experienced patent analysts delivers patentability, freedom-to-operate, invalidity, and landscape searches to law firms, in-house IP teams, R&D; organizations, and inventors who rely on accurate prior art to make high-stakes decisions.
We pair that domain expertise with our own software. Quartet, our AI-enabled patent search platform, integrates AI and Boolean search techniques to help professionals find better prior art, faster. We have a small development team in Barcelona and offer both remote and co-working options. Duet is an agentic AI application for anyone needing to find, understand, or interact with patent data. Users ask natural-language questions about inventions, prior art, portfolios, and claims. This is applied AI engineering in production, not model training or demos.
We're looking for an AI Product Engineer who efficiently ships outcomes. Your job is to chart a path to the end-state, sequence the unknowns so you're never blocked on a single big bet, and put working functionality in the users’ hands at every stage. The focus is on thin vertical slices that compound to produce impressive features.
Concretely, that means extending Duet's agent harness: integrating new data sources, building MCP access to Duet functionality, and authoring curated prompts and skills. The AI Product Engineer needs to bring their expertise to these processes to implement robust and cutting-edge solutions with incremental wins along the way.
Start from outcomes,



not design requirements. You translate user needs into solutions with a staged delivery plan that brings value to the user in each sprint.
We are a small company that values the voice of every team member. We expect every engineer to become familiar with the world of intellectual property and to bring your ideas and talents to the table so that we can create the best possible solutions for our customers.
We live the spirit of agile – we are radically transparent, we take introspection seriously, and we constantly adapt and improve. MCP server access
Design and implement our approach to expose Duet's capabilities via MCP.
Rapid data integration
Add new data sources by writing thin TypeScript connectors and wiring them into the agent as composable tools. Take the lead to understand the data source and find the most efficient way to incorporate it into Duet.
You’ll work on context management, streaming, Redis locks, billing, presentation to the user, etc.
Fluency in written and verbal English
~3+ years professional software engineering experience, with strong TypeScript/Node backend skills
~12+ months building LLM agents, with an emphasis on integrating orchestrating complex tools and data sources
~ Demonstrated prompt engineering as product work - structured prompts, iteration from failure modes, version control
~ mphasis on integrating orchestrating complex tools and data sources
~ Demonstrated prompt engineering as product work - structured prompts, iteration from failure modes, version control
~

📌 AI Product Engineer (Agent & Integrations) (Barcelona)
🏢 Ensemble IP
📍 Barcelona