B2B | Fullstack (Python, Next & React) Developer | Barcelona, Spain

Optiwisers; Barcelona; On-site; EUR 60,000 - 90,000; Full time

Job summary

Optiwisers in Barcelona, Spain, is seeking a Senior Full Stack Developer to join an AI-driven product team. You will work across frontend and backend using Next.js, React, Python and FastAPI, building scalable web applications in a Scrum environment.

You’ll implement responsive UIs with Tailwind CSS, integrate APIs, write tests with pytest and Playwright, and deploy on AWS. Collaboration with designers, product managers and other engineers will be vital to deliver high‑quality features.

Qualifications

• 4+ years of professional full stack development.
• Experience with Next.js and React in production.
• Experience with Python backend development and FastAPI.

Responsibilities

• Develop and maintain web applications using Next.js and React.
• Build responsive user interfaces with Tailwind CSS.
• Collaborate with backend engineers to design, integrate and test APIs using Python and FastAPI.
• Develop and maintain backend components in Python.
• Write and maintain automated tests using pytest, Playwright, and related tools.
• Work with AWS cloud services to ensure scalability, reliability and security.
• Troubleshoot, debug and optimize applications for performance and scalability.
• Mentor junior developers and share best practices.

Skills

Next.js

React

Tailwind CSS

Python

FastAPI

AWS

Git

Scrum/Agile

pytest

Tools

Docker

GitHub Actions

TurboRepo

Storybook

Playwright

Job description

B2B | Fullstack (Python, Next & React) Developer | Barcelona, Spain

About the Role

We are looking for a Senior Full Stack Developer to join an innovative team working on AI-driven solutions.

You will contribute to the development of scalable and high-performing web applications, working across both frontend and backend technologies. You’ll be part of a collaborative Scrum Agile environment, working closely with developers, designers and product managers to deliver high-quality solutions.

What You’ll Do

• Develop and maintain web applications using Next.js and React.
• Build responsive and modern user interfaces using Tailwind CSS.
• Collaborate with backend engineers to design, integrate and test APIs using Python and FastAPI.
• Develop and maintain backend components in Python.
• Write and maintain automated tests using pytest, Gherkin, Cucumber and Playwright.
• Work with AWS cloud services, ensuring applications are scalable, reliable and secure.
• Troubleshoot, debug and optimize applications for performance and scalability.
• Work with charting libraries such as ECharts, Chart.js or Recharts.
• Participate actively in Scrum ceremonies, including daily stand-ups, sprint planning and retrospectives.
• Collaborate with designers, developers and product managers to deliver new features.
• Contribute to code quality, security and development best practices.
• Mentor junior developers and provide technical guidance when needed.

What We’re Looking For

• 4-5+ years of professional experience in Full Stack Development.
• Strong experience with Next.js and React.
• Experience building responsive UIs with Tailwind CSS.
• Experience with Python and backend development, ideally with FastAPI.
• Hands-on experience with AWS services such as EC2, S3, Lambda and RDS.
• Experience with automated testing and pytest.
• Familiarity with Git and modern software development practices.
• Experience working in a Scrum/Agile environment.
• Experience with charting libraries such as ECharts, Chart.js or Recharts.
• Strong problem-solving and analytical skills.
• Good communication and teamwork skills.
• Comfortable working in a fast-paced environment and dealing with ambiguity.

Nice to Have

• Experience with CI/CD pipelines, particularly GitHub Actions.
• Experience with Docker and containerized applications.
• Knowledge of serverless architectures.
• Experience with SonarCloud or Snyk.
• Familiarity with TurboRepo / monorepos.
• Experience with Storybook for UI component development.
• Experience with Gherkin, Cucumber and Playwright.

If you're looking for an opportunity to work with modern technologies and contribute to innovative AI-driven products within a global aviation group, we'd love to hear from you.