Francisco Rosa

I work as a freelance Azure and .NET developer on Zellar, a sustainability platform helping SMEs reduce their emissions. Over the years I've evolved from building APIs to owning the cloud infrastructure, DevOps pipelines, and third-party integration layer across the entire platform.

• Developed and evolved the application's APIs using C#, .NET 6–10, EF Core, and SQL — working in an Agile/JIRA environment from requirements through to deployment.
• Led the migration of APIs to .NET 6, .NET 8 and .NET 10, and database layers to .NET Framework 4.8, modernising the platform's foundations.
• Refactored all APIs for Docker compatibility, set up an Azure Container Registry, and migrated the full API estate to a new Azure location — including App Services and DevOps pipelines.
• Built and maintained integrations with Mixpanel, Salesforce, Stripe, Perse (energy consumption), and Loqate (location services), publishing custom NuGet packages hosted in Azure DevOps.
• Designed and built the platform's own SSO system, enabling Zellar account login across third-party platforms like Circle.
• Developed a notification microservice using a message queue and the Outbox pattern to reliably deliver events to third-party integrations.
• Maintained and extended Azure DevOps pipelines and deployment configurations across all environments.
• Managed infrastructure across development, testing, and production in Azure — including App Services (scaling, networking, backups), SQL Servers (failover groups, audits), Blob Storage, Service Bus, Azure Functions, API Management, Azure Front Door, and Key Vault (secrets and certificates).
• Implemented Azure API Management to centralise, protect, and govern the platform's four APIs.
• Migrated all application secrets from app settings to Azure Key Vault, with automatic injection during deployment via Azure DevOps.

Worked as a freelance web developer for the learning and universities division, working on a solution for managing the courses’ recruitment websites, enrollment and integration with learning platforms. Some of the clients I worked for: EAE, VIU or CEAC. Last 4 months I acted as team lead managing a team of 6 developers, 2 QA and 1 BA

• Integration of two brands having to merge their data (students, enrollments, courses ...) to preserve their history.
• Solution for changing a conflicting NAS cabin where the documentation generated during the enrollment process (students and courses) was housed.
• I modified the two main applications behavior to historize the huge documentation that was generated in the enrollment process. Backup processes were simplified and the application performance was improved.
• I wrote a script in SQL to avoid a known exploit on the websites CMS that allowed to create super users.
• I participated as team lead in the upgrade of 3 Dotnet Nuke CMS, providing technical and functional help when required and carrying out the deployments.
• I finished a critical project for the organization such as the exercises/test’s editor migration from Flash to HTML5.
• As a team leader, I participated in planning and executing to change the application's payment provider due to a European regulatory change (3DS).

Due to a confidentiality agreement, it is not allowed to me to show publicly any description of any task nor any technology during my time in this startup.