Eng, former president of the Long Island Rail Road, will take the helm of the MBTA on April 10. The hiring brings to a close a months-long search to fill the top post at the T that Healey described as “probably the most important appointment I’ve had to make.”

As he introduced himself Monday, Eng, 61, professed a level of optimism about the agency that many riders likely abandoned long ago.

But advocates, union leaders, and colleagues who have worked with Eng said he has reason to be confident. He has a record of solving big transportation problems in New York with a hands-on, rider-centered approach, and those who know him well say he’ll find a way to do what has evaded so many before him in Boston.

“My pledge to the people of Massachusetts is that you will see meaningful, measurable steps being taken and progress being made in short order,” Eng said. “It’s clear that the MBTA service is not at the level that it needs to be, and it hasn’t been that way for far too long.”

Progress can’t come soon enough. Widespread slow zones, deep bus and subway service cuts, and long-delayed projects have worn riders’ patience thin. The T is short hundreds of workers as it tries to comply with federal safety mandates after a scathing federal report last year mandated dozens of changes.

Eng said he’s up to the challenge.

“I know that we’re going to turn this around,” he said. “I’m very engaged. I’m all in.”

Before he took over at the Metropolitan Transit Authority’s LIRR, where he was president from 2018 until early last year, the system had its own issues. The commuter rail system’s on-time performance was the worst in 18 years, the New York state comptroller found. Under his watch, on-time performance steadily improved.

Eng also made the seemingly impossible possible, said Lisa Daglian, executive director at the Permanent Citizens Advisory Committee to the MTA. A long-troubled project to add a third track to part of the commuter rail line to minimize delays “needed a champion” and Eng resurrected it, she said.

“He showed it was possible to bring divergent politics and organizations together to get such a significant project done,” Daglian said.

Leading LIRR and tackling big projects meant building consensus across dozens of towns, each with their own priorities and vision, Daglian said.

Eric Alexander, director of Vision Long Island, a nonprofit advocacy group focused on making communities more walkable, said he first met Eng in 2006 when his group was fighting against a series of road widening projects planned by the New York State Department of Transportation, where Eng was working as an engineer. Alexander said Eng was able to build consensus around a plan with bike and pedestrian amenities.

“That was going to go to a lawsuit or in the dustbin of history,” Alexander said of the original plan. “He found a way to undo that. He never raised his voice, he handled it. It gave me faith that there are people within bureaucracies that can do the right thing.”

Part of what makes Eng an effective leader is his ability to listen, said Anthony Simon, general chairman of the Sheet Metal Air Rail Transportation union that represents around 3,500 LIRR employees.

During the first two years of the COVID-19 pandemic, Simon said, he and Eng had daily phone calls about worker safety and how best to protect riders. Workers and riders can expect to see Eng out on the transit system asking them for feedback regularly, he said.

“He was a great communicator,” Simon said. “He’s going to listen to the commuters and the working men and women . . . They should give him a shot.”

Working within New York’s complex transit system is good preparation for Boston, which is smaller but, like New York, is a transit-dependent city with a “similar economy and political system,” said Thomas Glynn, a former general manager of the T and chief executive of Massport who helped lead one of Healey’s transition committees.

The MBTA’s problems are well-known in industry circles, Glynn said, even if the “T is seen as one of the biggest challenges at the moment.”

“But people are attracted to it because they like to solve a problem,” he said.

Throughout his career as chief engineer at New York’s state transportation department, chief operating officer at the MTA, and head of the LIRR, Eng regularly worked on and visited major projects throughout the state, where he’d often spend time chatting with workers on the site, snowplow drivers preparing for a major storm, or local officials and advocates closely watching a project’s progress, said Rosemary Powers, former chief operating officer for the transportation department and a former aide to Massachusetts Governor Deval Patrick.

“He’s a fixer,” Powers said of Eng. “He told me he’s looking for a challenge and he’s not ready to go out to pasture yet. I think he found it in the T.”

Eng will receive a five-year contract with a base salary of $470,000 a year, according to Healey’s office. That’s roughly $130,000 more than base pay of former T general manager Steve Poftak.

Eng is also be eligible to receive a $30,000 annual “retention payment” starting in July 2024 and so-called success bonuses worth as much as 10 percent of his base salary in 2024 and 15 percent in 2025, according to his contract, which also includes an $80,000 relocation payment. The bonus would be worth as much as 20 percent of his base salary in the years after.

“It’s really good day for Boston, it’s a really good day for the Commonwealth,” Healey said. “We are turning the page and moving forward and what I think is a really strong direction.”

Boston Mayor Michelle Wu, praised Eng’s selection.

“I’m so excited,” Wu said during a Monday appearance on WBUR. “We’ve been ready for this moment.”

Wu, who rode the MBTA regularly for years and said she still takes it roughly once a week, said, “It really feels like things have frayed to a point where everybody is just so discouraged and demoralized. . . . We need leadership at this moment.”

Stacy Thompson, executive director of the advocacy group LivableStreets, said Eng’s experience with the nuts and bolts of running a train system fits the MBTA’s immediate needs.

“It’s not the sexy stuff, it’s not the ribbon cuttings. It’s literally getting the trains running on time,” she said. “And that seems to be what his specialty is.”

Eng’s appointment, however, doesn’t guarantee success, transit advocates said.

Jarred Johnson, the executive director for TransitMatters, said he wants to see Eng lay out a vision for the agency that goes beyond a simple “fix-it first mentality,” given the demands for more resources to help reshape the troubled agency.

“Putting someone new in charge without having a conversation about resources is rearranging deck chairs,” he said during a phone call while on the Orange Line. “I don’t want to be overly pessimistic, but I do want to underscore: I’m sitting on a platform right now and no one cares that there’s a new general manager.”

Eng will replace Jeff Gonneville, who has served as interim general manager since Poftak stepped down in January. Gonneville, who has worked at the MBTA for more than two decades, including a stint as its chief operating officer, will be “staying on with the administration,” Healey said, though his exact role wasn’t immediately clear.

“This is about building out a leadership team,” Healey said.

Danny McDonald and Travis Andersen of the Globe staff contributed to this report.