Can you explain the difference between vertical and horizontal scaling in system design?

In my final year project, I worked on developing a web application for a local non-profit organization. We designed it to be scalable so it could handle increased traffic during events. Initially, we implemented vertical scaling by using a powerful cloud server, which allowed us to quickly process requests. However, as we tested the app with more users, we realized this approach had its limits. We switched to horizontal scaling by deploying multiple servers behind a load balancer. This transition not only improved performance but also reduced downtime during peak times. It was a valuable learning experience on how to balance resources effectively.

During my time volunteering for a community event, we faced challenges with the registration system that had to handle a large number of participants. Initially, we had a single laptop for registrations, which was akin to vertical scaling. As more people showed up, the system struggled to keep up with demand. We quickly adapted by setting up multiple registration stations (horizontal scaling) to distribute the workload. This approach allowed us to efficiently manage the flow of participants. It taught me the importance of planning for scalability in any project, whether it's tech-related or event management.

In my first job at a startup focused on e-commerce, we experienced rapid growth during the holiday season. Initially, we relied on vertical scaling by upgrading our servers to handle increased traffic. However, as sales surged, we realized this was not sustainable due to cost constraints. We transitioned to horizontal scaling by utilizing cloud services that allowed us to add more servers as needed. This not only improved our site’s performance but also ensured we could manage customer demands without significant downtime. This experience highlighted the importance of choosing the right scaling strategy based on specific business needs.