About 5.2 million Americans are currently underemployed, defined as those who are seeking full-time work but receive fewer than 30 hours per week from their employer. In addition to this segment, there are those who work full-time jobs but are unable to find companies that offer flexible hours to pick up additional shifts.

Wonolo, an online staffing marketplace, is trying to fill this gap by connecting companies with interested workers. The San Francisco-based startup announced today that it has raised $13 million in a round led by Sequoia Capital, with partner Jess Lee joining as a board member. New investor Base10 and existing investors PivotNorth and CrunchFund also joined.

Wonolo originated as a project of Coca-Cola’s Founders program, which has since been shut down.

“The company provided us with capital and access to Coca-Cola’s brands, partners, employees, and facilities in exchange for solving a problem Coca-Cola encountered,” wrote Wonolo cofounder and COO AJ Brustein, in an email to VentureBeat. “We spent time observing and working alongside Coke’s operations team and noticed they were often faced with a stream of jobs that needed to be done immediately, and Coke wasn’t able to anticipate the demand.”

In late 2014, the project spun out of the Coca-Cola Company to become Wonolo, which now employs 30 people.

The startup says it is working with thousands of companies, including Coca-Cola, Papa Johns, and Uniqlo, which set a price for jobs filled through Wonolo. The fee varies depending on location and the type of work (i.e. delivery, stocking, fulfillment).

According to Wonolo, over 100,000 workers are seeking jobs across the platform, which is free for its users. Prospective candidates need to present a string of soft skills in order to qualify, including being positive, polite, and punctual.

“We also require a background check before workers join the platform so Requestors (the businesses) have a trusted source for on-demand work,” wrote Brustein. “From there, Requestors might opt for additional screenings, such as drug tests or skills verification.”

With the rise of the gig economy, it is becoming increasingly easy to find hourly work, but Brustein argues that this is not the case everywhere.

“Typically, if you don’t live in a major metropolitan area, you can’t make very much on Uber, Lyft, or TaskRabbit,” he wrote. “There’s no guarantee that you’ll make a certain amount based on the time you invest in completing a task or a ride. These companies have done a great job of bringing the gig economy to the forefront of the conversation and showing that flexible work is achievable, but for many workers, they need more certainty than those platforms can provide. With Wonolo, you know how much you’ll make up front.”

To date, Wonolo has raised a total of $25 million. It will use the fresh injection of capital to grow its community of workers and expand into new markets.

“We’ll also use the new funds to explore other verticals that make sense for our product and our community,” added Brustein. “We are focused on front-line jobs, but we believe the same staffing model used for delivery, stocking, or fulfillment could also apply to industries like nursing, trucking, or paralegal.”

Correction: An earlier version of this post attributed the responses to cofounder and CEO Yong Kim. The answers were from cofounder and COO AJ Brustein.