I invented a new term: Flavored Developers
What makes our industry interesting, is when developing a domain-specific project, the developers must become experts in that specific domain. They must understand all the ins and outs to translate that knowledge into code.
Any intersection between a developer and another domain will add a new flavor to the developer.
Flavored developers are priceless. They have discovered all the unknowns in the domain. They have solved all the technical problems for that domain. They can reproduce other systems built upon their existing domain-knowledge.
Once you hire a developer, consider his flavor. If you’re building an accountant system, hire a developer who has built accountant systems.