Gradle
The JVM build system that replaced Ant/Maven — Hans Dockter, 2007. Default build for Android (since 2013). DSL in Groovy or Kotlin.
Incremental, parallel builds. Build cache + Gradle Enterprise (commercial) deliver fast team builds. build.gradle.kts (Kotlin) is preferred over build.gradle (Groovy) for type safety.
Criticised for slow first builds, awkward error messages, complex DSL. Competitors: Maven (XML, older, more predictable), Bazel (hermetic), sbt (Scala focus).