Senior Software Engineer

Apollo Solutions; Brussel; On-site; EUR 65,000 - 90,000; Full time

Job summary

Apollo Solutions is seeking a Senior .NET Developer to join a technical team focused on authentication, authorisation and secure application integration. You will work on C#/.NET, REST APIs, and modern identity and cloud technologies, delivering secure software components and integrations.

Bring strong C#/.NET skills, knowledge of OAuth/OIDC/SAML2, and experience with Azure and Kubernetes to drive secure, scalable solutions in a DevOps-friendly environment.

Qualifications

• Proven C# / .NET development experience.
• Experience with REST / JSON / YAML APIs.
• Frontend frameworks: Vue.js, React or Blazor.
• LDAP and SQL Server experience.
• OAuth2 / OIDC / SAML2 knowledge.
• Git and DevOps practices.

Responsibilities

• Develop and maintain secure software components and services
• Build and integrate authentication and authorisation solutions
• Develop REST APIs and application integrations
• Work with identity and security standards across new and existing applications
• Support cloud-native development and DevOps practices
• Contribute to technical documentation, testing and code quality

Job description

We are looking for an experienced Senior .NET Developer to join a technical team working on authentication, authorisation and secure application integration.

This is a strong opportunity for a developer with a solid C#/.NET background who also has experience working with modern identity, security and cloud technologies.

• Develop and maintain secure software components and services
• Build and integrate authentication and authorisation solutions
• Develop REST APIs and application integrations
• Work with identity and security standards across new and existing applications
• Support cloud-native development and DevOps practices
• Contribute to technical documentation, testing and code quality

Must have:

• C# / .NET
• REST / JSON / YAML
• Vue.js, React or Blazor
• LDAP / SQL Server
• OAuth2 / OIDC / SAML2
• Git & DevOps

Additional experience:

• TypeScript
• PowerShell / Bash
• Docker
• Cryptography, PKI, certificates, keystores and hashing
• Experience with an Identity Provider, such as:
• Keycloak
• Okta
• Ping
• ADFS

You will be a senior .NET developer with strong software engineering fundamentals and hands‑on experience with authentication, identity and application security.

Experience working in cloud and DevOps environments, particularly Azure and Kubernetes, would be highly beneficial.