On: We saved $50k/year with a Go microservice coded in...

[any626]

Depends

You could have

    property_id, user_id, value(string)
    1 (assume age), 1213,    60
    2 (gender),     1213,    female

or

    property_id, user_id, value_str, value_int
    1 (assume age), 1213,    null, 60
    2 (gender),     1213,    female, null

or have a mapping in the application to get the type of the property. Plenty of ways to handle it.