Muhammad Ali is a software development expert with extensive experience in telecommunications and the air and rail transport industries. He holds a master's degree in the distributed systems course of the year 2006 from the Royal Institute of technology (KTH), Stockholm, Sweden, and holds a bachelor's honors degree in computer science from the University of Engineering & Technology Lahore, Pakistan.

He has a passion for software design and development, cloud and big data test-driven development, and system integration. He has built enterprise applications using the open source stack for top-tier software vendors and large government and private organizations worldwide. Ali has settled in Stockholm, Sweden, and has been providing services to various IT companies within Sweden and outside Europe.

Jeff Deskins has been building commercial websites since 1995. He loves to turn ideas into working solutions. Lately, he has been building most of his web applications in the cloud and is continuously learning best practices for high-performance sites.

Prior to his Internet development career, he worked for 13 years as a television news photographer. He continues to provide Internet solutions for different television stations through his website, www.tvstats.com.

Alvaro Garcia is a software developer who firmly believes in the eXtreme Programming methodology. He's embarked on a lifelong learning process and is now in a symbiotic exchange process with the Barcelona Software Craftsmanship meet-up, where he is a co-organizer.

Alvaro has been working in the IT industry for product companies, consulting firms, and on his own since 2005. He occasionally blogs at http://alvarogarcia7.github.io.

He enjoys reading and reviewing technology books and providing feedback to the author whenever possible to create the best experience for the final reader.

Esko Luontola has been programming since the beginning of the 21st century. In 2007, he was bitten by the TDD bug and has been test-infected ever since. Today, he has tens of projects under his belt using TDD and helps others get started with it; some of his freely available learning material includes the TDD Tetris Tutorial exercise and the Let's Code screencasts. He is also fluent in concurrency, distributed systems, and the deep ends of the JVM platform. In recent years, his interests have included Continuous Delivery, DevOps, and microservices.

Currently, Esko is working as a software consultant at Nitor Creations. He is the developer of multiple open source projects such as Retrolambda for back porting Java 8 code to Java 5-7 and the Jumi Test Runner in order to run tests faster and more flexibly than JUnit.