Ask HN: As a developer what are your aha moments?

1. The first language I ever used/learned was batch to script things in windows. When I learned python shortly after I recall it taking quite a bit of convincing myself to accept/use the "magic" of control flow being able to automatically jump back after a function returned as I was so used to manually wiring up all my gotos (was more of a painful experience than an 'ah-ha' I guess...)

2. When I was going through Tim Roughgarden's Algorithms course and saw the derivation of runtime complexity for mergesort and finally understood/visualized what a logarithm actually did (in school it was just taught as some rote function to help you manipulate eqautions of the form y=b^x)

3. Learning how TCP works from the bottom up. I think the biggest aha moment was when the textbook I was reading explained the TCP algorithm as a state machine that's just running on the client and server machines with the rest of the underlying network just forwarding packets, i.e. "pushing the complexity to the edge of the network".

4. Working through the nand2tetris project resulted in a lot of "oh X is just basically this at its core"

5. When going through a textbook explaining how relational database engines were implemented and seeing that they're essentially just using disk-persisted hash tables and self-balancing search trees to build indices on columns and make `select`s O(1)/O(log) time (I wasn't taught this in my uni's database course and assumed there was some fancy magic going on to make queries fast)

6. Realizing that I could just do a form of graph search/dependency resolution when learning a new codebase/trying to understand how a function works. I think before seeing someone do this in front of me I would usually just panic at the thought of "thousands of lines of code" rather than just "keep iteratively diving into the functions being called". Whenever I'm learning a new language, the first thing I'll do is setup the LSP plugin in vim so that I can quickly navigate up and down call graphs. Tbh I don't understand how some developers claim to not need this and instead just manually grep+open file in order to "jump to definition".

7. Forcing myself to derive the rotation logic for AVL trees. I was curious if, given just the high level properties of how an AVL tree behaves in order to guarantee O(log) time lookups, if I would be able to figure out all the rotation cases. Was a very rewarding exercise and something I plan on writing a blog post about (eventually...)

(edit)

8. Learning about the log data structure and how state can be replicated by replaying/executing this stream of transformations/updates.

from Hacker News https://ift.tt/3haayrU