Season scallops with salt and pepper. In a large sous vide bag, arrange them in a single layer with a bit of space between them. Add olive oil, then vacuum-seal the bag, maintaining the space between the scallops.
Place the bag in the heated water. Weigh it down if necessary to keep the scallops submerged during cooking. Set the timer for 30 minutes.
When the timer goes off, remove the scallops from the bag and pat them dry with paper towels. Reserve the cooking juice.
In a heavy-duty skillet, heat butter over medium-high heat until it begins to foam. Place the scallops in the skillet in a single layer, about 1 inch apart. Sear each side for about 20 seconds until golden brown, undisturbed. Transfer the scallops to a plate and cover to keep warm.
In the same skillet over medium-high heat, add shallot and capers, sauté for 1 minute, then add lemon juice and the reserved cooking juice. Stir in chopped parsley and red pepper flakes if using.
To serve, scoop some brown butter and caper sauce onto a warmed plate. Place 3-5 scallops over the sauce; scoop more sauce on the scallops if desired. Garnish with fresh parsley. Repeat with the rest of the scallops. Enjoy!