NEXT Insurance is a US based insurtech startup, revolutionizing the small business insurance industry. NEXT was founded 6 years ago and ever since we have been building our microservices in Kotlin. During this period we grew from a small startup with one backend developer(myself) to a $4B company with 150 backend developers. We have written over 1.2M lines of code in Kotlin and aquired long mileage with this programming language. In this talk I am going to share our experiences, insights and pains.