Shameera Rathnayaka is an Apache Axis2 Committer and a PMC member, and has been actively contributing to several Apache projects for the past few years. He holds a BSc Engineering (Hons) degree in Computer Science and Engineering from the University of Moratuwa, Sri Lanka. He first started his open source contributions with the Apache Axis2 project, where he implemented JDK7 Enum support for Apache Axis2, as well as a stream-based, high-performance solution for JSON<-->XML lossless transformation. A two times Google Summer of Code program participant with the Apache Axis2 and Apache Airavata projects, he is currently working on the project named JSON support and JSON to XML bidirectional conversion for Apache Airavata.

He currently works as a software engineer at WSO2 Inc, an open source enterprise middleware company based in Sri Lanka, where he is a member of the WSO2 Carbon team. His main research interest is Distributed Computing.

Karim Varela, the lead Android engineer at Tinder, has almost 10 years experience in mobile application development. He is currently responsible for building Tinder's Android application from the ground up. He is also leading SocialTagg, a startup whose aim is to connect people at events in a better way.

He was a technical reviewer for the book Pro Android 4 and is studying for his MBA from the University of Florida. He holds a bachelor's degree in Computer Science from the University of California.