I often hear it said that devs should use slow machines and connections for development. That's a great idea (and it can be simulated) in theory, but in practice very few people are going to buy old ThinkPads to test on. So a solution should probably be done in software, i.e. at the level of compilers and runtimes.

i.e. if JS engines weren't so fast, bloated frameworks would be impossible, even on dev hardware.

So I'm wondering if just like C++ compilers have optimization levels, perhaps there should be negative optimization levels, where all your code runs 10x slower by inserting dummy instructions (or perhaps a browser for testing that uses a naively implemented JS engine).

This would allow you to directly experience the pain you're causing without leaving the comfort of your fancy dev machine.

Then again by the sound of it, the release build of the app running on v8 already takes 10 sec to load, so we have already achieved the goal of gross lag without special tooling, so clearly people just don't care (or are working in systems where they feel powerless to fix it)?