Being at a large company isn't what made the difference. Even though I didn't realize it at the time, I think it is more important to work at a company that sells software and sees software development as a profit center and not a cost center.

There are some requirements I would look for:

1. Do they have automated tests?

2. Do they enforce code reviews?

3. Do they use some type of continuos integration system?

4. Do they use source control - preferable Git?

5. For the server side, do they use a statically type language - Java, C#, or even NodeJS/TypeScript

6. Do they have organized training sessions like lunch and learns?

I'm at a point in my career now where I'm pretty confident in what I know and I'm the only architect at my company. I ask for advice a lot from some of my former more experienced coworkers on a private Slack channel that we still use.