Mario AriasMario Arias is a software engineer and Spring certified instructor with more than 12 years of experience in software development and design, databases, training material design, and training delivery. He currently works as a software engineer in Mancester, UK, for Cake Solutions Ltd., a BAMTECH media company.Mario is well-known member of the Kotlin community and is part of the Arrow team, the group that developed and maintains the Arrow functional library. In his free time, he rides his bicycle and trains Brazilian Jiu-Jitsu.Rivu Chakraborty is a Caster.io instructor, Google Certified Android Developer, and senior tech member of Institute of Engineers (India). With more than 5 years of experience, he is currently working as a senior software engineer (Android) at Indus Net Technologies Pvt.Ltd.Rivu is a Kotlin and Android enthusiast and a Kotlin evangelist. He has been using Kotlin for more than 2 years. Rivu is the founder organizer of Kotlin Kolkata UG. He is also a core organizing team member of GDG Kolkata. Rivu has previously authored, Reactive Programming in Kotlin, and is working on two more books on Kotlin. Read More Read Less