What are the key differences between REST and GraphQL APIs?

During my final year project at college, I worked on a web application that required data from multiple sources. I initially used REST APIs to fetch data for my application. I learned how REST operates through endpoints, where each resource had its URL. However, I found that fetching related data often required multiple API calls, which could slow down the user experience. This challenge led me to explore GraphQL, where I could retrieve all the data I needed in a single request. This experience taught me the importance of choosing the right API architecture based on the requirements of the project.

While volunteering for a non-profit organization, I helped develop a tool to track donations and beneficiaries. We initially set up REST APIs to manage our data. Each time we needed to gather specific information, like the total donations per beneficiary, we had to make several calls to different endpoints. After discussing with my team, we decided to implement GraphQL to simplify our data retrieval process. With GraphQL, we could request only the data we needed, resulting in faster responses. This experience highlighted how the choice of API can directly impact the efficiency of an application.

In my first job as a junior developer, I was tasked with integrating third-party services into our application. The team primarily used REST APIs for this purpose, and I quickly learned how to structure requests and handle responses. However, as our application grew, we faced challenges with performance due to too many API calls. This led us to experiment with GraphQL for new features. By allowing clients to specify exactly what data they needed, we improved the application's performance significantly. This experience showed me the importance of adapting API strategies based on project scale and complexity.