Open sourced under Apache 2 license, IntelliJ Platform is the base for a number of well-known IDEs. It supports a large variety of languages and technologies via bundled plugins as well as thousands of third-party plugins. This talk will showcase the tooling and ecosystem for plugin developers, covering the whole lifecycle of creation and maintenance. We'll start by taking a look at the IDE features for development and testing: smart code insight, highlighting, and refactorings. How to keep up with the latest platform releases? Plugin Verifier allows you to check for any incompatibilities locally as well as get reports for already published versions. The built-in exception reporter provides the data for the Exception Analyzer, which helps collect and (auto-)triage all user-submitted runtime problems.