OAKLAND — Credit Karma will expand its Bay Area operations to a big downtown Oakland office tower, the tech company said Wednesday, in a deal that represents a fresh burst of economic expansion for the East Bay’s largest city,

The fast-growing financial services technology upstart will retain its current San Francisco headquarters, even after moving into the sleek new Key at 12th office tower in downtown Oakland.

“Credit Karma signed a lease for five floors, plus a roof deck, totaling 106,000 square feet, at 1100 Broadway in Oakland,” Credit Karma said Wednesday in comments emailed to this news organization.

The expansion to the East Bay will enable Credit Karma to use the BART system to link two company employment hubs so workers can zip back and forth between the offices by using the train line.

“With more than 1,000 employees, the company identified the site because it would allow the company to grow together in another building that is easily accessible via BART from the company headquarters located at 760 Market St. in San Francisco,” Credit Karma said.

The company is expected to move to the new downtown Oakland offices by sometime in 2020.

“Access to top talent residing in the East Bay and Fremont area” was one of the factors cited by Credit Karma for its expansion to downtown Oakland.

Plus, Credit Karma also believes that an expansion to downtown Oakland could significantly improve the commutes for numerous current workers.

“The majority of Credit Karma employees who reside outside of San Francisco live in the East Bay,” Credit Karma said.

Credit Karma’s deal comes on the heels of other major tech company expansions in downtown Oakland.

“This is great momentum for downtown Oakland,” said Benjamin Harrison, a senior vice president with Colliers International, a commercial real estate brokerage.

In December, Square, a financial services tech company, announced that it had leased all of the office space in downtown Oakland’s Uptown Station complex. The office portion of Uptown Station totals 356,000 square feet, which is enough space to accommodate roughly 1,700 workers or more.

Marqeta, a tech company that provides a card issuing and processing platform, has been expanding in downtown Oakland as well.

“These deals represent a coming of age for fintech companies,” said Edward Del Beccaro, an executive vice president with TRI Commercial, a commercial real estate firm.

New office and residential towers, as well as additional hotels, are expected to sprout on the Oakland skyline. Those new developments could well spur the East Bay city’s boom.

“In the next six months to a year, downtown Oakland is going to change for the better and much more than it has in recent years,” Harrison said.

Downtown Oakland in years past primarily grew when office rents spiked and spaces dwindled in San Francisco. When space became more plentiful in San Francisco, tenants ignored Oakland.

This time around, experts believe, downtown Oakland appears more capable of self-sustaining growth.

“Before it was just non-profits fleeing high prices in San Francisco, then it was back office operations moving to Oakland,” Del Beccaro said. “What’s happening now is an affirmation that downtown Oakland has arrived.”