Web services have been at the core of modern application architectures for many years. Regardless of what language or platform a developer is using, grasping how web services work and how to implement them are critical skills. In this course, we will step through how to work with several popular technologies to build web services. We begin by laying the groundwork for the course, explaining what web services are and the benefits they provide. We then offer a comparison of several popular web service technologies — REST, SOAP, and GraphQL — describing each technology's messaging formats in detail, along with examples of coding in several languages using a variety of server- and client-based implementations. Plus, get coding excerpts in Java, Python, and Swift.