Senior Fullstack Developer (React, TypeScript, TDD/ATDD)

About the Opportunity

Agile Thinkers is looking for a Senior Fullstack Developer to collaborate on a long-term software product development engagement for one of our clients.

We're looking for an experienced engineer with strong hands-on expertise in React, JavaScript, TypeScript, automated testing and Extreme Programming (XP) practices.

You'll work in a collaborative engineering environment where developers regularly work in pairs, share technical decisions and take collective responsibility for software quality.

This position requires solid technical autonomy. You should already be comfortable applying TDD, ATDD, automated testing and DevOps practices independently.

Key Responsibilities

• Design, develop, test and maintain software features across frontend and backend systems.

• Work regularly in pairs, applying pair programming and collaborative development practices.

• Participate in mob programming sessions where applicable.

• Apply Test-Driven Development (TDD) and Acceptance Test-Driven Development (ATDD) as part of everyday engineering.

• Independently design, implement and maintain unit, integration and regression tests across the full stack.

• Contribute to CI/CD pipelines, automated quality checks and DevOps practices.

• Refactor code to improve maintainability, reliability and software quality.

• Collaborate with engineers and product stakeholders to clarify requirements, acceptance criteria and expected behaviour.

• Contribute to technical discussions, problem-solving and continuous improvement.

Essential Requirements

• Experience: Approximately 5–7 years of professional software development experience, including substantial fullstack development experience.

• Frontend: Strong hands-on experience with React, JavaScript (ES6+) and TypeScript.

• Backend: Proven experience designing, developing and maintaining backend applications, services and APIs.

• TDD and ATDD: Solid practical knowledge and demonstrated ability to apply both independently in production development.

• Automated Testing: Strong experience designing, implementing, maintaining and troubleshooting unit, integration and regression tests across frontend and backend.

• DevOps and CI/CD: Practical experience with continuous integration, continuous delivery, build pipelines and automated quality controls.

• Extreme Programming: Experience with XP engineering practices, including continuous refactoring, collective code ownership and collaborative development.

• Pair Programming: Comfortable working regularly in pairs, sharing implementation, technical decisions and problem-solving responsibilities.

• Technical Autonomy: Ability to independently investigate problems, make sound engineering decisions and deliver maintainable, tested software.

• Languages: Fluent Portuguese and English at C1 level or above.

Nice to Have

• Experience with Behaviour-Driven Development (BDD).

• Experience with mob programming or ensemble programming.

• Experience improving automated testing strategies and CI/CD workflows.

• Experience in product-oriented engineering teams.

• Familiarity with cloud platforms and modern deployment environments.

What We Offer

• Long-term collaboration: Initial 12-month B2B engagement, with the possibility of renewal.

• Collaborative engineering: Work alongside experienced engineers in an environment that values shared ownership, technical quality and continuous feedback.

• Professional development: Opportunities for continuous technical and non-technical learning.

• Hybrid working: Combine remote collaboration with weekly on-site work.

Engagement Details

Contract: Independent Contractor / B2B Service Agreement (recibos verdes or company invoicing).

Availability: Full-time availability expected.

Duration: Initial 12-month engagement, with the possibility of renewal.

Location: Lisbon, Braga or Coimbra, Portugal.

Residency requirement: Candidates must currently reside in Lisbon, Braga, Coimbra or their surrounding areas.

Working model: Hybrid, with mandatory on-site attendance once per week at the assigned office location.

Languages: Portuguese (fluent) and English (minimum C1).

If you're an experienced fullstack engineer who enjoys collaborative development and has strong practical experience with TDD, ATDD, automated testing and DevOps, we'd like to hear from you.

Please submit your CV, highlighting your experience with React, TypeScript, fullstack development, automated testing and XP practices.