Less than six months after launching, the Uber Bus program for developing cities is showing strong adoption as the company plans to add staff to its Seattle-based engineering team.

“We’re seeing the growth of this product take off faster than UberX did when it launched in [those cities] — really early on, there are signs of product market fit,” said Miraj Rahematpura, a product manager on the high capacity vehicles team, the company’s internal name for the Uber Bus program. “We’re super excited to scale to a lot more cities.”

Rahematpura made the comments at a recruiting event for engineers and data scientists on Tuesday evening at Uber’s engineering office in Seattle.

Uber first launched the bus service late last year as a low-cost transportation option in Cairo and Monterrey, Mexico. Uber has more than 70 open positions in Seattle, but the company did not say how many it was hiring for the Uber Bus program. Uber already employs 350 people in Seattle and expanded its real estate footprint last year with room for up to 750 employees.

Shared taxis are common in many countries outside of the U.S. — they’re called microbuses in Egypt and peseros in Mexico. Uber said the service will help lower commuter costs and cut down on city congestion. The company currently charges the going rate for shared taxis, around $0.25 per ride in Cairo.

Uber is entering the bus business because its carpooling service Uber Pool is still 10 times more expensive than buses and vans in many cities around the world, which means its platform is still out of reach for billions of city-dwellers globally.

The company hopes to attract riders by cutting down commuter times, which can average an hour or two in Cairo, Rahematpura said.

While most shared taxis follow predetermined routes, Uber Bus will build on the tech company’s acumen for matching riders who share a similar destination. The platform was built using some of the same algorithms developed for Uber Pool.

Uber faces local competition from Cairo-based startup SWVL, a bus share platform that offers commuters rates that are 70 percent cheaper than a ride-hailing fare. In the U.S., the challenges of creating a viable shared van service for commuters was highlighted by the closure of Chariot, a platform owned by Ford that was shuttered earlier this year.

More than three years ago, Uber tested a carpool service in Seattle called uberHOP — GeekWire reporter Taylor Soper said it felt like “riding a private bus.” It used designated pickup spots and packed up to six passengers together on a handful of pre-determined routes. Uber shut down that pilot after seven months.

Uber now offers a similar service with Express Pool, its cheapest option, which also directs riders to a pickup spot.

Uber hasn’t announced plans to expand Uber Bus to other cities and is focusing instead on refining its product in Cairo and Monterrey, said Eoin O’Mahony, a senior data science manager at Uber. “Every city is different. We’re very much trying to build the right technological platform that we can go and deploy in that city,” he said.

Eventually, the company hopes to combine share services like Uber Bus with its other “last mile” transportation options such as electric bikes and scooters.

“We’re adding more and more modes of transportation and we’re excited about the prospect of stitching those together,” O’Mahony said.

Uber in February also began selling bus and train tickets within its app.