25Friday

25Friday is a consulting company specializing in the complete cycle of online product management. It has experts in investment, product management, development, architecture, QA, and infrastructure, allowing them to be the business and technology partner for startups.
About company

Software development engineer - c#/.net (medior)

Remote

location Porto, Braga, Aveiro

date June 26, 2026

types Full-time

wage 44k-52k EUR

Software Development Engineer - C#/.NET (Medior)

Portugal

Hybrid

Key Responsibilities

  • Design, develop, and maintain high-performance, scalable, and reliable backend services using C# / .NET Core;
  • Build and evolve microservices-based architectures, integrating internal systems and external partners;
  • Implement and maintain systems integrations with internal platforms and external partners;
  • Optimise application performance, identifying and resolving bottlenecks in high-load environments;
  • Participate in code reviews, ensuring code quality, maintainability, and best practices;
  • Collaborate closely with product owners, architects, and external partners to understand business processes and data models;
  • Actively participate in Scrum ceremonies, including daily stand-ups, refinements, and retrospectives;
  • Contribute to multiple integration projects in parallel, adapting to external dependencies and waiting times;
  • Produce and maintain technical documentation, including system designs and integration specifications.

Required Qualifications

  • Degree in Computer Science, Software Engineering, or a related field (or equivalent experience);
  • 4+ years of professional experience in software development;
  • Strong hands-on experience with C# / .NET Core;
  • Solid background designing and working with microservices architectures and systems integration;
  • Proven experience with performance optimisation in high-traffic systems;
  • Experience working with REST APIs and relational and/or NoSQL databases;
  • Experience with automated testing (unit, integration, end-to-end);
  • Experience working in an Agile environment (Scrum and/or Kanban);
  • Proactive mindset: challenges solutions rather than blindly following specifications;
  • Clear and effective communication skills, both verbal and written, with a good working level of English;
  • Ability to work collaboratively in cross-functional teams, including stakeholders in the Netherlands and Portugal.

Nice-to-Have Skills

  • Experience with RabbitMQ or other message brokers;
  • Familiarity with CI/CD pipelines, Docker, and a DevOps mindset;
  • Experience with Dapper or similar lightweight ORMs.

Why you will love to work with us

  • In the heart of the city of Porto, Aveiro and Braga, you'll have an amazing office with a parking lot, lots of food and equipped kitchens.
  • We offer you a transport allowance and an Uber Eats weekly budget. I know, right?! Going to the office has never been easier!
  • Health insurance (extendable to your household without extra costs), personal time off and flexible working hours.
  • Extra vacation days by longevity within the company and the possibility to work abroad for up to 6 weeks.
  • You will live our culture of learning - we are committed to your development so we love to share and learn with each other, alongside an annual budget for learning and development.
  • Each employee is rewarded with an Annual Bonus based on tenure.
  • You can further develop your English through private lessons.
  • You will emerge in a state of the art technology and exciting challenges.
  • We believe in building relationships at work. That’s why we organise several team outings and happy hours moments throughout the year.
  • And much more.