As a dev you usually stumble upon it for the architecture / coding part. But those are just details. The Domain part is all about the business: where do you add value, what things you can outsource because they're not at the heart of your strategy, which projects should get your better people etc. So I think it can be a good bridge for people who come from tech and want to dabble in the business part of their company.
Pros: I learned how to listen to customers, create proposals that tend to close, and upsell... all while being able to build the end product. This has helped me to close a good number of side projects after I moved back to working for larger companies.
Cons: The challenge working as an engineer in these small firms is that your resources are limited to the budget of the customer, which can be too small to do top-notch engineering work. You can generally find the balance without sacrificing too much quality, but you will never be completely satisfied with your work-product.