What is Plaid? Plaid is a third-party service provider used by Alliant and other financial institutions to make it easier for their users to seamlessly use multiple apps and account aggregators (like Venmo or Robinhood), without having to log in to each app individually.107 Alliant’s adoption of Plaid technology makes it easier for you use the tools and apps of your choice to make financial transactions and manage your money without the hassle of repeated logins during each session.