CTEs are low-key one of the best features of SQL. Great for debugging big queries, such as:

  with source as (
    select * from wherever
  ),
  transformed as (
    ...
  ),
  joined as (
    ...
  ),
  final as (
    ...
  )
  select * from final

You can switch `final` to `transformed` to see what the query is doing internally. Almost like having good control flow. Almost.