100% agree, I don't want the senior engineer to know by hart how to code the algorithm that solves a specific problem, but I want them to know which algorithm to use for which problem, how to navigate a graph? use Depth First or Breadth, how to get the shortest path, use Dijkstra, do they need to know how to code Depth First or Dijkstra, NO! also Senior engineers are team players, they connect teams and help shorten the time it takes to understand a problem by composing it to smaller solvable problems that can be scaled on the team of junior engineers, that's the real value of the senior engineer.