Senior Full Stack AI Native Developer

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. Requirements 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). Benefits Why You'll Love Working With Us • High-Impact Role: Be a key player in a small, agile team building a greenfield project with the potential to transform an industry. • Modern Technology: Work with a cutting-edge, carefully selected tech stack with a focus on best practices. • Growth & Learning: Gain deep experience in AI-driven applications, cloud-native architecture, and real-time systems. • Stability & Vision: Enjoy the energy of a startup environment backed by the resources and stability of a large, successful company. • Collaborative Culture: We value open communication, teamwork, and a shared passion for building exceptional products. • Growth and career development • At Leadtech, we prioritize your growth. Enjoy a flexible career path with personalized internal training and an annual budget for external learning opportunities. • Work-Life balance • Benefit from a flexible schedule with flextime and the option of working full remote or from our Barcelona office. Enjoy free Friday afternoons with a 7-hour workday, plus a 35-hour workweek in July and A