Senior Full Stack AI Native Developer
leadtech • Spain
Posted: June 1, 2026
Job Description
As part of the Development team as a Full-Stack Developer, you will be instrumental in building and scaling our platforms and products. You will work across our entire A.I technology stack to deliver a seamless and powerful user experience. You will be joining projects with a shipping fast approach and a modern tech stack.
- Extensive knowledge of Javascript/Typescript.
- Design, implement, and maintain RESTful APIs with NextJS/Express to manage user authentication, data processing, and orchestrate analysis workflows
- Model Context Protocol (MCP) Knowledge Agents with Claude SDK: to Build AI agents access to real-time data, APIs, and tools Create AI Agents that can actually take actions, Combine the reasoning power of LLMs with real-world integration
- Build AI Agents with LangGraph + LangFuse that can handle multi-step reasoning, Create workflows where AI agents collaborate or hand off tasks to other agents. Maintain conversation state and context across interactions and Handle complex decision trees and conditional logic
- Develop and maintain features on both our React frontend and Node.js (NextJS) backend.
- Build intuitive user interfaces using TypeScript, Vite, React and our UI component library, enabling users to upload media, manage their analyses, and interact with our web delivered product.
- Integrate our platform with various external services like Payment Service Providers and APIs, and handle incoming webhooks for processing asynchronous tasks
- Collaborate closely with AI product managers and AI specialists to translate complex requirements into robust, scalable features expressed in AI design prompts.
- Contribute to database schema design and write migrations for our PostgreSQL & BigQuery databases.
- Knowledge of GCP to Collaborate with the team on application deployment and help maintain our cloud infrastructure on Google Cloud Platform.
We are seeking a proactive and skilled developer who is passionate about building modern, data-driven applications.
- Extensive experience with the Python framework
- Deep API Integration experience with 3rd Party vendors. Being able to work with multiple types of SDK to integrate into our products quickly.
- A serious self-learner and someone that adapts to new tools and platforms very quickly and adapts it into their day to day workflow in days.
- TypeScript Proficiency: You are highly proficient in TypeScript and its application in both frontend (React) and backend (Node.js) environments.
- Frontend Expertise: Strong experience with React and modern state management, including Hooks and the Context API.
- Backend Expertise: Solid experience building and consuming REST APIs with Node.js and NextJS or Express.
- Database Skills: Experience with like PostgreSQL, and working with an ORM or query builder.
- Knowledge of LangGraph, LangChain, LangFuse,
- Problem-Solving Mindset: You are a collaborative problem-solver, eager to take on new challenges and contribute to a fast-paced development cycle.
- Passion for AI: A genuine passion and awareness for artificial intelligence and a strong desire to build products that leverage its capabilities to solve real-world problems. and bring those new discoveries to our product Portfolio.
- Very High Agency: in consultation with a Product Owner and the Engineering Manager, you must work with autonomy with a large degree of freedom to implement the business vision.
- Creativity and Proactivity: You have a passion for building great products, are eager to propose new features, and enjoy finding creative solutions to improve the user experience.
Nice to Have:
- AI Project Experience: Previous experience working on projects involving AI, machine learning, or interacting with large language models (LLMs).
- Familiarity with UI component libraries.
- Knowledge of cloud platforms like Google Cloud Platform (GCP).
Additional Content
As part of the Development team as a Full-Stack Developer, you will be instrumental in building and scaling our platforms and products. You will work across our entire A.I technology stack to deliver a seamless and powerful user experience. You will be joining projects with a shipping fast approach and a modern tech stack.
- Extensive knowledge of Javascript/Typescript.
- Design, implement, and maintain RESTful APIs with NextJS/Express to manage user authentication, data processing, and orchestrate analysis workflows
- Model Context Protocol (MCP) Knowledge Agents with Claude SDK: to Build AI agents access to real-time data, APIs, and tools Create AI Agents that can actually take actions, Combine the reasoning power of LLMs with real-world integration
- Build AI Agents with LangGraph + LangFuse that can handle multi-step reasoning, Create workflows where AI agents collaborate or hand off tasks to other agents. Maintain conversation state and context across interactions and Handle complex decision trees and conditional logic
- Develop and maintain features on both our React frontend and Node.js (NextJS) backend.
- Build intuitive user interfaces using TypeScript, Vite, React and our UI component library, enabling users to upload media, manage their analyses, and interact with our web delivered product.
- Integrate our platform with various external services like Payment Service Providers and APIs, and handle incoming webhooks for processing asynchronous tasks
- Collaborate closely with AI product managers and AI specialists to translate complex requirements into robust, scalable features expressed in AI design prompts.
- Contribute to database schema design and write migrations for our PostgreSQL & BigQuery databases.
- Knowledge of GCP to Collaborate with the team on application deployment and help maintain our cloud infrastructure on Google Cloud Platform.
We are seeking a proactive and skilled developer who is passionate about building modern, data-driven applications.
- Extensive experience with the Python framework
- Deep API Integration experience with 3rd Party vendors. Being able to work with multiple types of SDK to integrate into our products quickly.
- A serious self-learner and someone that adapts to new tools and platforms very quickly and adapts it into their day to day workflow in days.
- TypeScript Proficiency: You are highly proficient in TypeScript and its application in both frontend (React) and backend (Node.js) environments.
- Frontend Expertise: Strong experience with React and modern state management, including Hooks and the Context API.
- Backend Expertise: Solid experience building and consuming REST APIs with Node.js and NextJS or Express.
- Database Skills: Experience with like PostgreSQL, and working with an ORM or query builder.
- Knowledge of LangGraph, LangChain, LangFuse,
- Problem-Solving Mindset: You are a collaborative problem-solver, eager to take on new challenges and contribute to a fast-paced development cycle.
- Passion for AI: A genuine passion and awareness for artificial intelligence and a strong desire to build products that leverage its capabilities to solve real-world problems. and bring those new discoveries to our product Portfolio.
- Very High Agency: in consultation with a Product Owner and the Engineering Manager, you must work with autonomy with a large degree of freedom to implement the business vision.
- Creativity and Proactivity: You have a passion for building great products, are eager to propose new features, and enjoy finding creative solutions to improve the user experience.
Nice to Have:
- AI Project Experience: Previous experience working on projects involving AI, machine learning, or interacting with large language models (LLMs).
- Familiarity with UI component libraries.
- Knowledge of cloud platforms like Google Cloud Platform (GCP).