An Internal Developer Platform (IDP) is built by platform teams within large enterprises using a combination of open source, commercial, and in-house tools. It reduces ticket ops, standardizes config setups and workflows, cuts lead time and time to market (TTM). A well-designed IDP follows a platform as a product approach and can enable true DevOps. Unlike PaaS solutions, IDPs are not readily available as off-the-shelf solutions and cover the software delivery cycle end-to-end including infrastructure orchestration, application configuration, deployment management, environment management, and RBAC. The architecture of an IDP consists of five main planes: Developer Control Plane, Integration and Delivery Plane, Resource Plane, Monitoring and Logging Plane, and Security Plane. A Minimum Viable Platform (MVP) is a representative first version of the platform in the context of a "HelloWorld" scenario and should be built before expanding to an enterprise-grade IDP.