This chapter mainly talks about the crucial contributions of API gateway solutions to empower microservices to be the right and rewarding ingredient for producing enterprise-scale, mission-critical, cloud-hosted, service-oriented, event-driven, innovation-filled, process-aware, production-grade, and business-centric applications. We discuss popular API gateway solutions in this chapter. We also implement an aggregation service through the API gateway. The source code for the microservices (order service, customer service, and aggregation service) are deposited in the book's GitHub. The GitHub link for the book is https://github.com/PacktPublishing/Hands-On-RESTful-API-Design-Patterns-and-Best-Practices.