I've never really figured out a test to tell if the company is going to fall into that category without actually working at the company.

It's not as simple as "BigCo" vs startup; I've worked at startups where layoffs were frequent enough that it devolved into existence justification, and I've worked at BigCos that actually did give a fair bit of leeway in how you do things (within some degree of reason).

The closest thing to a "rule" that I've come to is if they use a less-mainstream language; if they're routinely using Haskell or something, they're probably a bit more onboard with experimentation, but that's still not a hard and fast rule.