Karyn Brockman will serve as finance director, while Ty Matsdorf will serve as campaigns and communications director.
Brockman most recently worked as finance director for Sen. Chris Murphy (D-Conn.), helping him raise more than $10.5 million to face Linda McMahon, one of the best-funded Republican Senate contenders in the nation.
Matsdorf most recently worked as war room director and senior adviser for American Bridge 21st Century, the Democratic super-PAC affiliated with opposition research group American Bridge.
Majority PAC spent nearly $40 million last cycle and found success in a large majority of the races in which it invested.
Then, Democrats faced a tough fight to retain the majority in the Senate, with a number of early retirements and incumbents in competitive presidential states complicating their efforts, but the party eventually managed to pick up seats.
Democrats face a similarly challenging map this cycle, as they're defending nearly twice as many seats as Republicans, seven of which President Obama lost.