Senior AI-Native Full-Stack Developer (Remote/Barcelona)

Agency Industry; United States; Remote; USD 120,000 - 180,000; Full time

Benefits offered by this job

Annual learning budget

Flexible work hours

Remote or Barcelona office access

Job summary

Leadtech Group is seeking a Senior Full‑Stack AI Native Developer for Barcelona or Remote. You will build and scale AI-powered platforms across the full stack, from NextJS/Express APIs to React/TypeScript frontends, collaborating with AI product managers to translate complex requirements into robust features.

You’ll work with LangGraph, LangChain, LangFuse to enable multi‑step reasoning, integrate with external services, and contribute to PostgreSQL/BigQuery data workflows in a cloud environment.

Qualifications

• Proactive developer with passion for building modern data‑driven apps.
• Extensive experience with the Python framework.
• Strong API integration experience with 3rd party vendors.
• Highly proficient in TypeScript for frontend and backend.
• Solid React experience with modern state management.
• Experience building REST APIs with Node.js/Next.js/Express.
• SQL experience with PostgreSQL and ORM/query builders.
• Knowledge of LangGraph, LangChain, LangFuse.

Responsibilities

• Design, implement, and maintain RESTful APIs with NextJS/Express to manage user authentication, data processing, and orchestration of analysis workflows.
• Build AI Agents and workflows using LangGraph/LangFuse and ensure robust multi‑agent coordination.
• Develop and maintain features on both our React frontend and Node.js (NextJS) backend.
• Create intuitive UI with TypeScript, React, and our component library for media uploads and analyses management.
• Integrate platform with external services and handle webhooks for asynchronous tasks.
• Collaborate with AI product managers and AI specialists to translate requirements into scalable features.
• Contribute to database schema design and migrations for PostgreSQL & BigQuery.

Skills

Python

TypeScript

React

Node.js

Next.js

REST APIs

PostgreSQL

LangGraph

LangChain

LangFuse

API integration

Cloud deployment (GCP)

Tools

Express

LangGraph

LangChain

LangFuse

Job description

Leadtech Group is seeking a Senior Full‑Stack AI Native Developer for Barcelona or Remote. You will build and scale AI-powered platforms across the full stack, from NextJS/Express APIs to React/TypeScript frontends, collaborating with AI product managers to translate complex requirements into robust features.

You’ll work with LangGraph, LangChain, LangFuse to enable multi‑step reasoning, integrate with external services, and contribute to PostgreSQL/BigQuery data workflows in a cloud environment.