The PS5's DualSense is an excellent controller, but its traditional button/analog stick layout is a small disadvantage compared to mouse-and-keyboard setups in fast-paced competitive games. This mod adds an extra button designed to let you jump, crouch, or dodge without moving your aiming finger from the right joystick, thereby saving you a few potentially life-saving milliseconds in gunfights.
Youtuber makerunit was kind enough to provide a detailed, high-quality tutorial on adding external buttons to the PS5 DualSense controller. Though the process looks simple enough, you will need two different screwdrivers, some cables, a soldering iron and wire, a glue gun, a drill, and of course a button of your choice to complete the mod.
The end result is a DualSense controller that's slightly uglier than the unmodded version - though you could remedy that somewhat with a button that's flush with the curve of the controller and a little less excess glue - but no doubt more efficient in competitive first-person shooters.
To clarify, I probably wouldn't recommend trying this unless, A) you play a lot of competitive games and desperately crave the tiniest advantage, and B) you have some experience using the above tools and taking apart electronics.
It's also worth noting that a recent patent suggests Sony could be releasing an attachable back button for the DualSense that could serve a similar purpose to this mod. Still, the above video's worth a watch just to see everything that goes into adding an extra button to a controller like the DualSense.
Here are the best PS5 games to play with your modded or unmodded DualSense.