Presumptive Democratic presidential nominee Joe Biden’s campaign has gone on a hiring spree, addressing concerns from some in his party who say it has been slow to staff key positions on the digital side and in battleground states ahead of the November general election against President Trump.

Over the weekend, the Biden campaign brought on Caitlin Mitchell, the chief mobilization officer for Sen. Elizabeth Warren’s (D-Mass.) now-ended presidential campaign, to scale up the former vice president's digital operations.

The campaign has also hired Andrew Gauthier, a veteran of Sen. Kamala Harris’s (D-Calif.) suspended presidential campaign and former BuzzFeed video chief, to create new content. Robyn Kanner, who worked on former Rep. Beto O’Rourke’s (D-Texas) unsuccessful presidential campaign, is helping to design a new website for Biden, among other “visual brand operations.”

Rob Flaherty, the digital director for the Biden campaign, said his team will double in size in the coming weeks.

That news comes as a relief to Democrats, who have been worried that the Biden campaign was not taking its digital outreach efforts seriously enough at a time when the candidate has been confined to his home because of the coronavirus outbreak. A virtual rally last week in Florida, for example, was beset by embarrassing technical glitches.

Democrats have also said that the Biden campaign has lacked basic digital elements including a coherent messaging strategy, events that allow supporters to engage directly with the former vice president and a social media plan that coordinates the sharing of campaign material among top surrogates.

The Trump campaign, meanwhile, was built around a digital strategy and routinely pulls off the kind of large-scale events that the Biden campaign has struggled to accomplish. Trump's campaign manager, Brad Parscale, has described his operation as the “Death Star.”

Adriel Hampton, who runs a digital marketing firm in California, told The Hill that the new round of hires is “good news for the Biden campaign” but that there’s “lots of catch-up to do, for sure.”

In addition to the new digital hires, the Biden campaign has brought on Jenn Ridder, the former campaign manager for Montana Gov. Steve Bullock’s (D) ended presidential bid, to act as battleground states director.

Molly Ritner, who led Biden’s Super Tuesday efforts during the primary, will be the campaign's deputy states director.

The Biden campaign has also hired a handful of new deputies to work under Manu Varghese, its chief operating officer.

Saloni Multani, a partner at a venture capital firm in California, will act as chief financial officer. And Deanna Nesburg, the former treasurer for Harris’s presidential campaign, will be a senior adviser for financial operations.

Some Democrats in key battleground states had been worried that the Biden campaign would be outmatched.

The Biden campaign operations were set back because of the coronavirus. Biden effectively pulled away in the race for the nomination in early March, but was then quickly sidelined by the coronavirus outbreak, which caused the campaign to rethink its hiring and outreach strategy.