Senior Full-Stack Engineer - AI-Powered Platform (Remote)

5Blue Software; España; Remote; EUR 60,000 - 90,000; Full time

Benefits offered by this job

Flexible Work Environment: Remote work

1:1 English Classes

Premium Medical Insurance

Great international team

Equipment provided

Accounting support

Paid time off: 18 days vacation + 7 s

Flexible payment options

Job summary

5Blue Software is seeking a Senior Full-Stack Developer to join an international team building an AI-powered B2B platform. You will own features end-to-end, from design to production, across frontend and backend, while applying an AI-first approach.

You’ll collaborate with engineering and product teams across time zones, use Claude Code or similar tools, and drive architectural decisions. Fluency in English and strong problem-solving are essential.

Qualifications

• 5+ years of professional software development experience.
• 2+ years of professional React experience.
• Strong practical experience with TypeScript.
• Hands-on experience with Express, Fastify, or a similar API framework.
• Strong full-stack capabilities across frontend and backend.
• Production experience with microservices architecture.
• Hands-on experience with AWS, GCP, or Azure.
• Relational and non-relational databases (e.g., PostgreSQL, MongoDB).
• Experience integrating third-party REST APIs into production systems.
• Experience building AI-powered features in a real product.
• Experience using AI-assisted coding tools (e.g., Claude Code).
• Ability to write, understand, debug, and validate code without relying on AI tools.
• English proficiency at B2 level or higher.
• Experience in a product-focused engineering environment.

Responsibilities

• Build end-to-end features using React, TypeScript, and Node.js.
• Develop frontend experiences for a complex B2B product.
• Design and implement backend services, APIs, and business logic.
• Integrate AI-powered features into production environment.
• Contribute to system design, architecture, and technical decisions.
• Use AI-assisted development tools as part of workflow.
• Review, test, debug, and validate AI-generated code.
• Work with relational and non-relational databases.
• Contribute to CI/CD, testing, deployment, and DevOps processes.
• Collaborate with Engineering and Product to clarify requirements.
• Participate in Agile ceremonies with distributed teams.
• Communicate reasoning and trade-offs in English.

Skills

Full-stack development

React development

TypeScript

Node.js

CI/CD

Tools

AWS

GCP

Azure

Docker

Kubernetes

PostgreSQL

MongoDB

REST APIs

LangChain

Job description

5Blue Software is seeking a Senior Full-Stack Developer to join an international team building an AI-powered B2B platform. You will own features end-to-end, from design to production, across frontend and backend, while applying an AI-first approach.

You’ll collaborate with engineering and product teams across time zones, use Claude Code or similar tools, and drive architectural decisions. Fluency in English and strong problem-solving are essential.