Rafael Sellés Vizcaíno

Backend Developer

Making mobility safer and easier for millions of users in Latin America and Europe.

I am currently part of the Governance team, working to solve one of ride-hailing's toughest challenges: keeping drivers and riders safe without making their lives harder. I build systems that verify identities, monitor service quality, and flag anomalies while upholding the seamless user experience expected of a modern mobility platform.

Before this, I led the rollout of social authentication for the Rider team. SMS-based verification was expensive and often annoyed users, especially those who traveled or changed phone numbers. We added social logins from Apple, Google, and Facebook, which made signing in faster and safer while cutting SMS costs. This change made onboarding smoother and helped users recover their accounts more easily.

On the Payments team, I helped manage the PSD2 migration, a big regulatory change that could have affected our payment systems. I worked with the Fraud team to improve detection systems and streamline payment processes, balancing compliance and user experience. This work kept us ahead of European regulations and helped maintain high payment success rates, which directly affected revenue.

Senior PHP Developer

Updating legacy ticketing systems for the world's largest self-service event platform.

I joined the Supercreators team to rebuild B2B ticketing tools that were slowing down enterprise customers. These clients, like conference organizers and music festival producers, needed more control, better reports, and quicker setup. By updating the self-service process, we opened up new revenue opportunities and made support easier.

Our biggest project was migrating a key legacy service that accounted for over 40% of Eventbrite's fee income. The old system was fragile, hard to maintain, and risky for the business. The new system was stronger, easier to update, and let the team release features faster without worrying about breaking important revenue streams.

Senior Backend Developer

Scaling a mid-term rental platform by automating property management and expanding distribution.

Spotahome's growth relied on getting more quality properties and showing them to renters quickly. On the Integrations Team, I built custom connectors to third-party platforms so landlords could manage listings across multiple channels from a single dashboard. This cut down on manual work, improved accuracy, and sped up property acquisition.

One big problem was outdated occupancy data, with properties shown as available when they were not. This frustrated renters and wasted sales efforts. I improved the property management system to sync occupancy in real time, boosting conversion rates and freeing local teams from manual updates and complaints.

I also led the development of Spotahome's public API, which served as the foundation for partnerships with other platforms. By sharing property data and booking workflows through a well-designed API, we enabled large-scale distribution and opened up new revenue streams without adding extra work for the team.

Senior PHP Developer

Building the technical fundations for a fast-growing startup environment.

Pingvalue was scaling rapidly, and the legacy infrastructure couldn't keep up. The APIs were tightly coupled with Google App Engine, limiting our ability to scale and manage environments effectively. I led the move to Kubernetes, which removed vendor lock-in. The new setup made scaling easier, reduced costs, and helped new developers get started faster.

I also helped shape the technical culture by promoting RESTful API design, test-driven development, and continuous integration. These practices allowed a team of over 20 developers to deliver reliable software for web, iOS, and Android.

Senior Web Developer

Improving the developer experience for the global community of Delphi and C++.

Embarcadero's Developer Network was the central hub where thousands of developers accessed documentation, tools, and community resources. I developed features that improved discoverability, streamlined downloads, and made it easier for developers to get the most out of Embarcadero's products. The main goal was to make it easier for developers to use the tools they needed to build software.

One big project was bringing the Community, a social network for developers, into the larger ecosystem. This meant moving old databases, building REST APIs, and connecting user profiles, forums, and product resources. This work helped create a more active developer community and gave useful feedback to the product team.

Web Developer

Running a 24/7 SMS marketing platform that served TV networks, brands, and agencies across Spain.

SMS was the primary channel for real-time engagement, including live voting for TV shows, quiz competitions, and mobile alerts. Our platform powered campaigns for major clients. I managed integrations with multiple SMS providers, ensuring high availability and cost efficiency.

The main technical challenge was making the system reliable. I built services to queue, route, and deliver messages at scale, and I kept costs down by sending traffic to the best provider based on price and performance.

I also created marketing tools that used SMS, email, and mobile apps together, giving clients better ways to reach their audiences. This work helped clients run data-driven campaigns and provided analytics to demonstrate their return on investment.

Junior Web Developer

Helping small and medium businesses set up and grow their online presence.

I worked on projects ranging from corporate websites to digital marketing campaigns, always focused on making technology accessible to clients who weren't technical.

I also mentored new team members, teaching them company processes and best practices. Helping others improved my own understanding and built the communication skills I would need later in my career.