Hiring software engineers: should you look for overall experience or expertise of a specific language?

When hiring software engineers, should you place more weight on the expertise of the specific language or framework you are using, or overall skill and experience.

i.e. A great engineer with 10+ years of experience might not have used the Python programming language. But can likely learn it easily.

The downside I see is the temporary cost to the startup of such an engineer to learn your programming language or framework.

What do you suggest?

It depends on a few factors (some of which are both related):

1. What stage your startup is on?
2. Do you have the time and resources?
3. Do you already have a technical co-founder?
4. Does that technical co-founder have great overall experience?

If you're an early stage startup (and most at this stage have limited resources), I would recommend someone who already has experience with the specific language/framework you're building your product on.

But once you start to gain some traction and have more resources, hire great engineers regardless of their experience on your particular language/framework. Some of the best software developers I know aren't boxed into a particular language. They're generalists who are language-agnostic.