The blog post explores the inner workings of several built-in JavaScript methods by implementing them from scratch, which is often a common interview task. It examines the map, reduce, filter, debounce, bind, and sort functions, explaining how each operates and providing code examples for their manual implementation. The map function transforms arrays without altering the original, reduce combines array values into a single output, filter creates a new array based on a condition, debounce limits the rate of function calls, bind alters the scope for later function execution, and sort orders arrays using a merge sort algorithm. The post argues that reimplementing these methods enhances a developer's understanding and effective use of them, while tools like LogRocket offer improved debugging and context understanding for JavaScript errors.