API/Backend Developer

AdvanceWorks; Portugal; On-site; EUR 42,000 - 64,000; Full time

Benefits offered by this job

International team

Formal training and certifications

Challenging projects with modern tech

Flexible hours and autonomy

Job summary

AdvanceWorks is seeking an experienced Backend .NET Developer to design, build and evolve secure APIs for a Nordic healthcare client. You will work in a cross-disciplinary team on cloud-native services, ensuring robust security, compliance and code quality.

The role emphasizes API-first development, maintainable architectures, and ownership of meaningful parts of a regulated, high-impact system. Fluency in English and a passion for learning are essential.

Qualifications

• 3+ years with .NET 5+ and .NET 8+ in the last 3 years.
• Proven ability to write SQL by hand in backend code.
• Experience with automated unit/integration tests (xUnit/NUnit).
• Experience designing long-lasting API systems (REST, JSON, OpenAPI, auto code generation).
• Experience with access control and MFA.
• CI/CD, IaC and automated quality gates.
• Security-by-design and OWASP Top 10/CWE.
• Knowledge of GDPR.

Responsibilities

• Design, develop and maintain backend services and REST APIs in .NET 8+ and ASP.NET, following an API-first approach.
• Structure API systems using FastEndpoints / REPR or MVC for maintainability and scalability.
• Write and optimize SQL queries and database logic by hand (Dapper/ADO.NET).
• Build and maintain automated unit and integration tests (xUnit/NUnit).
• Implement claims-based access control and MFA, and make sensitive data actions traceable.
• Apply security-by-design and defend against OWASP Top 10/CWE vulnerabilities.
• Contribute to CI/CD pipelines, IaC and automated quality gates; ensure code quality with SonarCloud.
• Build cloud-native services for Kubernetes with resilience patterns and proper secrets management.
• Take ownership of work packages and act as point of contact with stakeholders.
• Collaborate with cross-functional teams to support digital transformation.
• Contribute to responsible AI usage when building software handling personal data.

Skills

.NET

SQL

Unit tests

API design

Security

CI/CD

GDPR

English

Collaboration

Learning

Tools

xUnit

NUnit

OpenAPI

Dapper

ADO.NET

Kubernetes

Job description

At AdvanceWorks, we learn, grow, and have fun together. And we do all this while creating great software solutions for clients across many industries and geographies.

We are constantly challenging ourselves and each other to use the latest technologies and the best methodologies and make sure we walk the talk.

Exciting as it may sound, we also have our red lines: each of us is a unique person, with unique opinions, beliefs, options, interests, hopes, and fears. With the right to speak its mind, be mindful of the common goals, and always be constructive.

The way we respect each other, discuss different points of view, and challenge ourselves and each other while tackling our common challenges makes us strong. United. Brave. And sure that there will be a better tomorrow, even when we do mistakes. Because we learn from our failures and successes.

What will be your role

We are looking for an experienced Backend .NET Developer (API/Backend) to join a project for a Nordic client in the healthcare sector. You will help design, build and evolve secure APIs that are meant to last for many years and that handle sensitive personal and clinical data.

This opportunity is ideal for professionals who are passionate about clean API design, cloud-native architecture, security-by-design and code quality. It suits people who enjoy working in cross-disciplinary teams and taking ownership of meaningful parts of a solution in a regulated, high-impact environment.

Key Responsibilities:

• Design, develop and maintain backend services and REST APIs in .NET 8+ and ASP.NET, following an API-first approach (JSON, OpenAPI definitions and automatic code generation).
• Structure API systems that must last for many years using proven architectures such as FastEndpoints / REPR or MVC, so they stay maintainable and scalable over time.
• Write and optimize SQL queries and database logic by hand, using lightweight data access tools such as Dapper or ADO.NET.
• Build and maintain automated unit and integration tests (e.g., xUnit, NUnit) following recognised conventions.
• Implement action-based access control (claims-based, least privilege) and MFA, and make every action on sensitive data traceable.
• Apply security-by-design principles and implement defences against known vulnerabilities (OWASP Top 10, CWE), in line with data protection requirements for medical record information.
• Contribute to automated CI/CD pipelines, Infrastructure as Code and automated quality gates with no manual steps. Keep code quality high with tools such as SonarCloud, with warnings treated as errors.
• Build cloud-native services for Kubernetes that scale horizontally, using resilience patterns (retry, circuit-breaking) and proper secrets management.
• Take ownership of defined work packages, deliverables and technical decisions, and act as the point of contact with stakeholders when needed.
• Collaborate with cross-functional teams and stakeholders on shared objectives, supporting the client’s digital transformation and strategic goals.
• Contribute to the responsible and structured use of AI when building software that handles sensitive personal data.

Who will work by your side?

You will work as part of a team on a project and also with the AdvanceWorks team, a team of experts, and thus become part of a team of people who care about each other. Amazing people and professionals who are proud of their technology and leadership skills yet eager to learn from you and be challenged.

You'll also work side by side with our clients, spanning a wide range of industries and countries. And that means working with more bright minds, being empathetic about each other, and always keeping in mind that every brilliant piece of software we produce has two objectives: to achieve a specific business goal, and to make the people who built it as successful as you want to be.

What should you bring to the team?

• At least 3 years of cumulative experience with .NET 5+ (.NET Core 3.1 also counts; .NET Framework 4.x does not). This must include developing and releasing with .NET 8+ and ASP.NET within the last 3 years.
• Proven experience writing SQL by hand in backend code as the main way of accessing data in your projects.
• Experience building and maintaining automated unit and integration tests with recognised libraries (e.g., xUnit, NUnit) and conventions.
• Experience designing API systems built to last for many years (FastEndpoints / REPR or MVC), with REST, JSON, OpenAPI definitions and automatic code generation.
• Experience with action-based access control (claims-based, least privilege), MFA and making actions on sensitive data traceable.
• Experience with automated CI/CD pipelines, Infrastructure as Code and automated quality gates without manual steps.
• Experience applying security-by-design and implementing defences against OWASP Top 10 and CWE vulnerabilities.
• Solid knowledge of information security and data protection (GDPR).
• Fluency in English.
• Commitment to quality and delivery excellence, with strong analytical and problem-solving skills.
• The capacity to listen & influence people and foster change in a collaborative way.
• The courage to question the status quo in a constructive and empathic way.
• An unshakable desire to keep on learning, and the willingness to share what you already know.

What is in it for you?

• Work with an international team;
• An amazing informal culture of smart hardworking and friendly people that support and care about each other;
• Be involved in strategic and operational initiatives beyond the scope of your main mission;
• Formal training and certifications in technology, methodology, and relational skills;
• Challenging projects with exciting clients and state-of-the‑art technology;
• A dynamic company where you can make a difference and where talent and results matter (and politics do not);
• Flexibility with responsibility;
• Happy hours and after‑hours feel‑good actions.