IMO it's best to start as clean as possible and start migrating logic into the database over time as performance or security needs arise. Same with clean code,

IMO it's best to start as clean as possible and start migrating logic into the database over time as performance or security needs arise. Same with clean code, start with it and if there are performance issues start adding shortcuts and conditions that might improve the performance but have a negative impact on readability and require much more comments.