Former employee sharing trade secrets with competitor - NDA worth anything?

I publish illustrative scenarios prepared by my practice. All participants and conversations are fictional. The fictional posts are not posts by real users, accounts of client experiences, or reports of actual results.
Illustrative scenario prepared by my practice.
For informational purposes only. Not legal advice.
Hypothetical question

I'm losing my mind over here. Our lead engineer left 3 months ago and just popped up at a direct competitor. Fine, whatever, people move on.

But now I'm hearing from industry contacts that they're using methods that are IDENTICAL to our proprietary process. Like, the exact same approach we spent 18 months developing. There's no way they independently came up with this.

He signed an NDA when he joined us. Is it actually worth anything or are these just pieces of paper that lawyers make us sign? What are my real options here?

Illustrative response

The auto-renewal trap is real. I signed a SaaS contract that auto-renewed with only 30 days' notice to cancel. Some states have laws against surprise renewals โ€” California's ARL requires clear disclosure and easy cancellation.