FA

Fernando Alvarez

Senior Back End Developer

Freelance backend development services — Java, Spring Boot and scalable APIs for teams that need to ship production-grade software.

Murcia, Spain

Available for new freelance projects · remote (EU time zones) or on-site

Email meHire me on MaltLinkedInGitHub

Freelance backend development

I'm a Senior Backend Developer originally from Archena, a small town in the Valle de Ricote, Región de Murcia — and still based there today, available for freelance and contract work, remote or on-site. I design and build backend systems in Java and Spring Boot, from authentication platforms handling OAuth 2.0 flows to high-throughput microservices communicating over Kafka, gRPC, REST and SOAP.

I've worked on OAuth 2.0 and Spring Authorization Server for Inditex at Capitole, built resilient microservices for the logistics industry at CTT Express, and years earlier my job at Universidad de Murcia was building on the open-source Sakai platform. Whether you need a new API built from scratch, an existing system hardened and scaled, or hands-on help shipping a feature, I bring production-grade Spring Boot experience to the table.

What I offer

Backend & API Development

REST, gRPC and SOAP APIs built on Java and Spring Boot, designed to scale from the first commit.

Authentication & Security

OAuth 2.0, Spring Security and Spring Authorization Server — login flows, SSO and access control done right.

Microservices & Messaging

Event-driven systems with Kafka, resilient inter-service communication and clean domain boundaries.

Cloud & DevOps

Docker, Kubernetes and CI/CD pipelines to get your backend running reliably in production.

Legacy & Platform Migration

Framework upgrades, monolith-to-microservices moves and on-prem-to-cloud migrations — planned and executed on production systems that can’t afford downtime.

Code Optimization & Refactoring

Profiling, refactoring and paying down technical debt in an existing codebase — faster response times and a system your team can actually maintain.

Websites for Individuals & Businesses

Full-stack builds and improvements for personal and small-business sites — from a simple landing page to a bespoke web app, designed and shipped end to end.

Consulting & Advisory

Technical guidance at any scale — from student and personal projects to performance optimizations and full projects for companies.

Portfolio

WelcomeToOurVerbena

View live project →

A scheduling platform for fiestas patronales, romerías, verbenas and festivals. Organizers build a shareable program of events, grouped by day, and publish it as a single link — ready to send over WhatsApp, no account needed to view it.

Shareable link

Every public program gets its own URL — no account needed to view it.

Day-by-day timeline

Every event of a multi-day fiesta, romería or festival, grouped clearly by day.

Auto-generated share images

One click turns the program — or a single day — into a ready-to-post Instagram Story image.

Custom branding

The organizer's own logo or title, on the program and on its share images.

Full multi-day schedule share image, generated from a real published programSingle-day schedule share image, generated from a real published program

Share images generated straight from a real published schedule

  • Java 25
  • Spring Boot 4
  • MongoDB
  • React
  • TypeScript
  • Docker
  • nginx
  • Stripe
See a live example: Fiestas de San Ejemplo →How it’s built: the full stack →

Let's work together

Available for freelance projects and contract work, based in Murcia, Spain and open to remote collaboration. The fastest way to reach me is email — tell me what you are building and I will get back to you. You can also hire me through Malt.

Email meHire me on MaltContact on LinkedIn