Interviewing After 10 Months at Current Job – Is It Okay to Talk About Projects from Previous Companies in Behavioral Interviews?

I recommend focusing more on your previous work experience for two reasons:

1. More impactful work.
2. Your FE depth >> fullstack breadth.

• Is it okay to talk about a favorite project from a previous company during behavioral interviews, even if it’s from over a year ago?

Yes, this is fine, esp. if you want to talk about an in-depth impactful project over a long time horizon.

But you can also bring up smaller examples from your current job as well (for suitable questions) in the context of feedback, conflict resolution, etc to avoid raising eyebrows by not referring to your current experience at all.

• Is there a “time limit” for how far back I can go when giving examples?

I like to stay within 5 years because that's about as far back as I can remember the details vividly. I think it's a bigger red flag to start with an example and then add that you don't remember it clearly :). I have seen my coaching clients bring up older examples when it's apt and they remember all the details.

• And does it ever make sense to talk about recent backend work when applying for frontend roles?

Yes, this would be fine, esp. to augment your deep FE experience with some shallow BE knowledge and show your e2e understanding. But I'd keep the focus on FE since that's what you're interviewing for and appear to be more interested in pursuing.

What you're facing is not very uncommon. Having a robust hash map of behavioral interview signals to your stories and preparing ahead of time are recommended to avoid being caught off guard and making suboptimal decisions thinking on your feet.