Senior AI Full Stack Developer (Full Remote) - 1014961622

leadtech; Barcelona; Híbrido; EUR 70.000 - 90.000; Jornada completa

Descripción de la vacante

A digital innovation firm in Barcelona is seeking a Senior Full-Stack Developer to join their innovative team building AI-driven platforms. Applicants should have over 5 years of experience, with strong skills in Python, TypeScript, and React. This role offers flexibility for remote or in-office work, a competitive salary, and a collaborative culture. Enjoy a comprehensive benefits package, including health insurance and vacation options, while contributing to a cutting-edge project that leverages AI technology.

Servicios

Flexible work schedule

Free coffee and snacks

Private health insurance

25 days of vacation plus birthday off

Unique office environment with views

Formación

• 5+ years of experience in full-stack development.
• Extensive experience with Python framework.
• High proficiency in TypeScript for both frontend and backend.
• Strong experience in React and state management.
• Solid experience in building REST APIs with Node.js.

Responsabilidades

• Build and scale the Project's platform utilizing AI agents.
• Develop features for the React frontend and Node.js backend.
• Design and maintain RESTful APIs.
• Collaborate with product managers and AI specialists.

Conocimientos

Python

TypeScript

React

Node.js

PostgreSQL

BigQuery

n8n.io

LangGraph

LangChain

Descripción del empleo

At Leadtech, we’ve been redefining digital businesses since 2009, creating innovative online solutions that reach millions of users every month. With a diverse team of over 700 members from 23+ nationalities, we’re united by a passion for creativity and collaboration.

We specialize in delivering user‑centric experiences across web and mobile platforms, where people can connect with our products like never before.

We’re proud of our global reach and committed to fostering an inclusive workplace where every individual contributes to our shared vision of bringing cutting‑edge projects to life. Learn more about our journey and mission on our About us! page!

About the role

We are building an innovative platform that leverages a suite of specialized AI agents to automate complex tasks. As a Senior Level Full‑Stack Developer, you will be instrumental in building and scaling the Project’s platform. You will work across our entire technology stack to deliver a seamless and powerful user experience. You will be joining a project with a clear vision and a modern tech stack.

• Extensive knowledge of Python.
• Develop and maintain features on both our React frontend and Node.js (Express) backend.
• Build intuitive user interfaces using TypeScript, Vite, and our Shadcn UI component library, enabling users to upload media, manage their analyses, and interact with our AI agents.
• Design, implement, and maintain RESTful APIs with Express to manage user authentication, data processing, and orchestrate analysis workflows
• Build AI Agents with LangGraph 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
• Model Context Protocol (MCP) Knowledge Agents with Claude: build AI agents with access to real‑time data, APIs, and tools; create AI assistants that can actually take actions, combine the reasoning power of LLMs with real‑world integration
• Integrate our platform with various external services and APIs, and handle incoming webhooks for processing asynchronous tasks
• Collaborate on the integration with our n8n‑based workflow automation engine, helping to connect our backend with the AI agents that power our analyses
• Collaborate closely with product managers and AI specialists to translate complex requirements into robust, scalable features.
• 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.

What We’re Looking For

• Experience: 5+ years of professional experience in a Senior full‑stack development role.
• Extensive experience with the Python framework.
• TypeScript Proficiency: 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 Express.
• Database Skills: experience with PostgreSQL, and working with an ORM or query builder.
• Experience in BigQuery.
• Knowledge of n8n.io, LangGraph, LangChain.
• Problem‑Solving Mindset: 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.
• Creativity and Proactivity: a passion for building great products, 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 like Shadcn UI.
• Knowledge of cloud platforms like Google Cloud Platform (GCP).

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.

If you are ready to take on a challenging and rewarding role at the intersection of AI and product strategy, we encourage you to apply.

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 (7‑9:30 a.m. start, 3:30‑6 p.m. end) 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 August so you can savor summer!

Comprehensive Benefits

• Competitive salary, full‑time permanent contract, and top‑tier private health insurance (including dental and psychological services).
• 25 days of vacation plus your birthday off, with flexible vacation options—no blackout days!

Unique Perks

• If you wish to come, in our office in Barcelona you’ll find it complete with free coffee, fresh fruit, snacks, a game room, and a rooftop terrace with stunning Mediterranean views.
• Additional benefits include ticket restaurant and nursery vouchers, paid directly from your gross salary.

Join us in an environment where you’re free to innovate, learn, and grow alongside passionate professionals. At Leadtech, you’ll tackle exciting challenges and be part of a vibrant team dedicated to delivering exceptional user experiences.

Sounds good? Apply now! We’re looking forward to getting to know you.

Equal Employment Opportunity Employer

Leadtech is an Equal Employment Opportunity (EEO) Employer, which means we encourage applications from people with different backgrounds, interests, and personal circumstances. Our team welcomes applicants regardless of their race, gender, age, religion, nationality, sexual orientation, and/or disabilities. All we need is your high energy, skills, and willingness to be a part of a great project!

Location

You’ll have the flexibility to choose whether you’d like to come to the office every day, from time to time, or work fully remote. We want you to find the best combination for you.

If you prefer to be surrounded with amazing people, our exceptional office is in Barcelona’s Blue Building, located right on the city’s seafront. Besides our stunning views, you’ll enjoy our office perks such as free fruit, snacks, and coffee and you’ll also be able to take part in our Mario Kart and table tennis competitions.

Personal data you provide will be processed in order to manage your candidacy for the corporate selection processes that fit your profile. If you wish, you can exercise your rights of access, rectification or cancellation by writing to our address (Avenida Litoral, 12‑14, 5ta planta. Barcelona. 08005) or to the email address [e-mail], attaching to your request a document that can validate your identity.