I'm a late twenties software engineer. Years ago I worked on a tiny team that was integrating an upstart financial product from a well known legacy company. Billions of dollars have flowed through the system integration. My company got a nice high six-figure "implementation" bonus for implementating it along with a small percentage of the money flowing throughout.

My team of a designer, product manager and two software engineers built this. We created millions of dollars in new revenue for our company.

Prior to this another off-shore team had tried to integrate something similar from our partner's competitor. They failed to complete the integration.

This is why good software engineers are paid so much.