If you are building new Android apps, Kotlin is better suited because it is the recommended programming language for Android. If you are a first-time programmer, Kotlin is also a better choice as it has safety features and concise syntax that will help you focus on learning core program fundamentals. You should note that in some cases, employers may seek out Android developers that have Java programming skills. For example, if you plan on joining an organization that already has an Android app, they may already be using Java. If they already have an app written in Java, it is unlikely they will want to redesign the app in a different language, such as Kotlin. Therefore, you should look at the job requirements to see if the job posting you are interested in lists Java as a required skill.