Martin Joo is a Hungarian software engineer and Laravel educator focused on the deeper engineering side of PHP work — performance, system design, and database internals — applied to the Laravel framework specifically. His material is denser than most Laravel tutorial content and aimed at developers ready to think about Laravel as a serious production stack.
His CourseFlix listing carries four Martin Joo courses: Performance with Laravel (Premium Package), Master System Design with Laravel, Building Finance Apps with Laravel, and Building a Database Engine (a from-scratch database implementation in PHP). Material is paid and aimed at senior Laravel developers and engineering leads.