I worked at a large tech company, not a FAANG though, and experienced much of the same as you. It took forever to get things done, and a large part of that was due to the dev environment. There were numerous internal tools that were not well documented. Etc.
I moved to working at start ups where the code is open source. Start ups move faster, and it's easier to use open source tools than internal/proprietary tools. At the large tech company, we couldn't use anything past C++03 (this was in 2016), due to technical constraints. At my start up, we use the newest C++ as soon as it comes out.
For what it's worth, the start up I work at now is fairly large and has a lot of code running in production. So I get the reward of pushing to prod, but the dev speed of a smaller company. Sure I take a pay hit, but I still make more than enough money, and I get to work on cool stuff.
I moved to working at start ups where the code is open source. Start ups move faster, and it's easier to use open source tools than internal/proprietary tools. At the large tech company, we couldn't use anything past C++03 (this was in 2016), due to technical constraints. At my start up, we use the newest C++ as soon as it comes out.
For what it's worth, the start up I work at now is fairly large and has a lot of code running in production. So I get the reward of pushing to prod, but the dev speed of a smaller company. Sure I take a pay hit, but I still make more than enough money, and I get to work on cool stuff.