Quick Comparison
| Kotlin | Java | |
|---|---|---|
| Null safety | Built-in | Optional class (verbose) |
| Boilerplate | Much less | Verbose |
| Coroutines | Built-in | Virtual threads (Java 21+) |
| Android | Preferred by Google | Supported |
| Interop | 100% Java interop | N/A |
| Jobs | Growing | Massive |
When to Use Kotlin
- Android development (Google’s preferred language)
- New JVM projects
- You want less boilerplate
- You want null safety built into the language
When to Use Java
- Enterprise environments that standardize on Java
- You need the largest talent pool
- Legacy codebases
- You want the most mature ecosystem
Verdict
Kotlin for new projects, especially Android. Java for enterprise and when you need the largest hiring pool. Kotlin’s 100% Java interop means you can adopt it gradually.