Kaiwan N Billimoria taught himself BASIC programming on his dad’s IBM PC back in 1983. He was programming in C and Assembly on DOS until he discovered the joys of Unix, and by around 1997, 

Linux! Kaiwan is the authour of four books on Linux (all published by Packt, UK): Hands-On System Programming with Linux Linux Kernel Programming Linux Kernel Programming, Part 2 (Char Drivers) Linux Kernel Debugging Kaiwan has worked on many aspects of the Linux system programming stack, including Bash scripting, system programming in C, kernel internals, device drivers, and embedded Linux work. 

He has actively worked on several commercial/FOSS projects. His contributions include drivers to the mainline Linux OS and many smaller projects hosted on GitHub. His Linux passion feeds well into his passion for teaching these topics to engineers, which he has done for well over two decades now. . It doesn’t hurt that he is a recreational ultrarunner too. He is currently working on the 2nd edition of Linux Kernel Programming.