Bad design is:
Rely on session for your data-flow
Bad design is:
Using ftp connection to loop: open a file, process the transaction, open another one, process...
Bad design is:
Not using temporary table to store unfinished transaction
Bad design is:
If your admin/management screen is so limited and messy, until you need to always query from database
Bad design is:
No filter and sorting for your data
Bad design is:
Store files in your database table
And if you still says that nothing wrong with your system...
Then that's is bad decision...
