Error handling

[phillip-le]

• differentiate between expected and unexpected
• You basically always want to log so you have to deal with unexpected errors every time even if all you do is catch log and throw
• HTTP Datasource pattern: check if it's a 2xx, runtime check the data, return
• Either monad, try/catch
• https://github.com/Sairyss/domain-driven-hexagon