I quit Amazon a couple weeks ago to start a startup, and I felt like I was reading my own story at some points. The tooling was the biggest thing dragging me back. It's hard to get excited about what you are building when you have to wait 2-4 minutes to preview your changes when most industry standard tools / stacks can do it instantly.

I left this feedback a bunch of times with different people in the org and I really hope they scrap their janky "frameworks" and dev tooling. They should just move to more standard open source tools options that evolve and get better quicker than barely maintained internal tooling.

Open Source tools also have bigger communities and resources online to debug and solve issues, compared to mediocre documentation from internal wiki. If absolutely needed, make thin wrappers above open source tools. Some other teams within Amazon had the luxury of using better tools, but I bet a lot of people are in the shoes I was in.