Proper deck post-beam-post connection
The usual length of 6x6 pressure-treated timber is 12', though you can get up to 24' (or longer) through special order, there is a rare need for that.
Technology around wood connectors has evolved and advanced rapidly, for your personal information use, I suggest visiting the &quot;Simpson Strong-ties&quot; website, to find the available hardware, cost, and uses. https://www.strongtie.com/