A rule enginerule engine without the operational burden.

1signal BlockAccount(user_id)
2signal SendVerificationEmail(user_id)
3 
4rule AccountApproval {
5    is_adult = input.age >= 18
6    allowed_country = input.country == "us" || input.country == "ca"
7    eligible = is_adult && allowed_country
8 
9    emit SendVerificationEmail(input.user_id) when eligible && !input.email_verified
10    emit BlockAccount(input.user_id) when !eligible
11 
12    out approved = eligible && input.email_verified
13}