A combination of software engineering and domain expertise makes for a really effective engineer. As an example - if you work as an software engineer in financ

A combination of software engineering and domain expertise makes for a really effective engineer. As an example - if you work as an software engineer in finance learn about a few particular financial products at the same level or better than your users, get a masters in finance, applied math, accounting and whatnot. This has the added benefit of staying relevant in the market when you age, as software engineering becomes increasingly commoditized.