Eric Lippert is one of the most authoritative voices on programming-language design from inside the field — a former senior engineer on the Microsoft C# compiler team and a long-running blogger (Fabulous Adventures in Coding) whose writing on language design has shaped how a generation of working developers think about C#, JavaScript, and the craft of language implementation.
His CourseFlix listing carries Fabulous Adventures in Data Structures and Algorithms — a deep treatment of algorithms and data structures from the perspective of someone who has built the compiler primitives underneath them. The teaching style is rigorous and unusually rich on the underlying CS theory.
Material is paid and aimed at engineers who want depth on algorithms beyond the interview-prep level. For broader content, see CourseFlix's Algorithms & Data Structures category page.