Re: Deck platform
If this a ground level deck then you certainly can end nail or screw the joists without hangers. If it's a raised deck you would be better off with using hangers ( as ed said --- why wouldn't you ? ) , besides you may be required to by local codes.
John mentioned the use of 2x2's ( ledger strip ) was used back in the day before hangers came along --- though 2X4's were used ( puesdo hanger ). This usually required notching the joists though --- unless you use a larger rim joist or beam than the joist .
There are times when I've built the frame on the ground first --- set it in place --- fill in with joists and decking after.
As ed also mentioned --- a fully finished deck will be heavy to move into place --- especially if it's a raised deck.
"" an ounce of perception -- a pound of obscure "