The shelf life is due to a business decision, where the knowledge the older person has is deemed insufficient to justify the compensation they've grown used to.
Sure, you love working with them and it's better for engineering, but the business wants college grads they can pay less, even if they don't do the same quality work.
Importantly, this doesn't have to be logical or good for the business. It just has to make sense in the context of quarterly targets.
More significantly, you can probably do things that no amount of entry-level engineers could do. The question is usually whether your (prospective) employer benefits from any of those things, whether they realise it or not.
As a former software guy, life long computer hacker, who moved to desktop support for years, I ran into new people hired as programmers who had to be coached to hit Ctrl-Alt-Del properly to log into their newly deployed laptop.
I'm working on hiring back into software roles now... I figure if the bar is that low, I can rock it out if I can just convince anyone that I can still code.
I keep hearing this but sometimes you just need hands on keyboard to push things out fast. Yes I can do a passable job at front end, middleware, databases, and I'm pretty adept at cloud infrastructure and devops. Does that mean I'm as valuable as 5 people? I can only do one of those at the same time.
It depends entirely on how much autonomy and motivation you have. I have to do all of that for my own modest product, but it's only viable because I have complete autonomy to decide what the most efficient approach would be... and I enjoy it.
This isn't typically how it plays out when you start a new job for someone else. Which means they won't reap the rewards of your experience until enough trust has been built to give you the autonomy to make it happen (this may never happen). So it takes time, and not everyone wants to take that time or can see the benefit, and arguably in the startup space there may not be enough runway for it either.
It’s not about autonomy. I work for a small company where I have a reasonable amount of control of how I implement anything. But, I can only do one thing at a time. At a certain point, you need more people to get anything done in a reasonable amount of time.
This may be true, but your company always wants the most business value, not the best/most elegant/most maintainable code. If you can deliver your boss's business interests at even 1.5x, I think you will have a long career.
The shelf life is due to a business decision, where the knowledge the older person has is deemed insufficient to justify the compensation they've grown used to.
Sure, you love working with them and it's better for engineering, but the business wants college grads they can pay less, even if they don't do the same quality work.
Importantly, this doesn't have to be logical or good for the business. It just has to make sense in the context of quarterly targets.