[binarymax]

I'll be brief and say the key to many successful careers has been to focus on data. Software, infrastructure, and everything digital is just scaffolding and piping to move and transform data in one way or another. So if you find some kind of data you enjoy working with or interpreting, then you can become an expert in that kind of data (the domain) and the problems and solutions that are related. Best of luck!

[bhu1st]

Never thought that specific data is what defines a domain.

Do you have other examples of this or a more elaborate form of explanation to this?

[philomath_mn]

I think they just mean the meaning of the data that comes through, which naturally consitutes the information important to that domain.

I work in fintech, the data points of my domain are transactions, prices, properties of different instruments, etc.

This data is moved + manipulated in different ways using different formats by different systems, but each day I accumulate useful context and expertise on the data of my domain.