Senior Fullstack Developer (.NET/React)

About the role

We are seeking a Senior Fullstack Developer to join an international technology company’s R&D team in Lisbon. The team builds an AI‑powered platform for a global fintech and insurance business, handling real‑time processing and high‑load workloads. You will work on cloud‑native applications using Microsoft and modern JavaScript technologies.

Key responsibilities

• Develop and maintain React‑based web applications and internal tools.
• Build clean, efficient, and scalable backend services with C# and .NET.
• Implement cloud‑native solutions on Azure (App Services, Functions, DevOps pipelines, SQL, etc.).
• Collaborate with Product, QA, and other stakeholders to deliver high‑quality features.
• Optimise performance, reliability, and security of applications.
• Participate in code reviews and drive technical improvements.
• Troubleshoot and resolve issues across the full stack.
• Adapt quickly to changing priorities and project needs.

Required profile

• 5+ years of professional C#/.NET development experience.
• 2–3+ years of hands‑on React and modern JavaScript (ES6+).
• At least 1 year of experience with Azure DevOps (CI/CD pipelines, repositories, boards).
• Proven experience with Azure cloud services (App Services, Functions, Storage, etc.).
• Strong SQL skills (Azure SQL, query optimisation, schema design).
• Fluent English (written and spoken); Portuguese is a plus.

Required skills

• C#
• .NET
• React
• JavaScript (ES6+)
• Azure DevOps
• Azure App Services
• Azure Functions
• Azure Storage
• Azure SQL
• SQL query optimisation
• Azure Service Bus (Topics) – nice to have
• Azure API Management – nice to have
• Power Apps – nice to have

What we offer

• Competitive salary package.
• Comprehensive benefits and wellbeing programme (health insurance, meal support, employee allowances).
• Hybrid working model in Lisbon.
• Opportunities for continuous learning and professional development.