|
Building things from first principles is a great way to instil understanding about how things work and why, which helps the understanding of problems later. When doing things for real in the workforce, reinventing core parts yourself is often not the best way, if only because you'll reinvent already fixed bugs too or that it wastes time, and that should be explained too. But understanding how things work below the outer layer of what would otherwise be black boxes lets you better understand when things go wrong, or have a better position to assess a pre-made library/service/other to be confident it is the most suitable option¹. Also, building things from scratch helps teach complexity analysis and, at a slightly higher level, security analysis, both of which are very useful, often vital, at much higher and/or more abstract levels. If building from first principles, or close to, is being drilled into students as the way to do things full stop, then those students are being taught poorly. It isn't how I remember learning way back when I was last called a student. For example my understanding of how b-trees and their relatives work, in part from having build routines to manage them in the dim and distant past, along with a number of other similar bits of knowledge, helps my understanding of how many DBMSs work in general and how certain optimisations at higher levels² do/don't work. I doubt I'll ever need to build any structure like that from anything close to first principles, but having done so in the past was not wasted time. The same with knowledge of filesystem construction, network protocols, etc. – I'll probably not use those things directly but the understanding helps me make choices, create solutions³, and solve problems, less directly. -------- [1] or at least a suitable option [2] things I do in the query syntax, what the query planner/runner can/can't do with that, etc. [3] I am sometimes the local master of temporary hacky solutions that get us over the line and allow time to do things more right slightly later instead of things failing right now. |