I have spent most of my career in software product development, meaning the code I wrote went into the products that made money for the company I worked for. I did a short stint writing internal software for the organization itself and the difference was very stark to me.
When you write software for your organization, it’s often to automate something and the driver is cost-reduction. The problem is that cost can only be reduced so much and eventually you are one of the biggest costs (in a budget owned by someone who likes to cut).
Revenue, on the other hand, can be very outsized compared to your cost. The budgets for product development are often expressed as a percent of revenue, so success increases budgets.
And, often, product development jobs offer some way to participate in that upside (options, RSUs, etc). Getting equity from an IT developer isn’t as easy.
It’s more complex than just “for-sale” or “internal”. When I was in FinTech, I wrote products, but my peers at banks, writing internal software, certainly drove revenue for their employers and were paid very well through generous bonus systems.
Pay is not the most important benefit. When you are critical to how a company makes money, you have bigger growth opportunities, more respect, and generally more clout. Product developers at software product companies have career prospects that lead all the way to CEO. That is not often the case for developers automating internal operations.