MENLO PARK, Calif. — On Tuesday, Facebook literally got a new face.

The company’s “big blue” app is undergoing a redesign: Its iconic blue bordering will be replaced by sleek, white trim in the coming weeks, and the service will be redesigned around groups and around private messages.

Symbolically, the redesign — announced at Facebook’s annual developer conference in the heart of Silicon Valley — represents Facebook’s yearning to present a fresh face to the world after years of troubles.

But beyond that cosmetic change, Facebook chief executive Mark Zuckerberg is only starting to craft answers for what the future will look like for the social media giant, which also owns Instagram, WhatsApp and Messenger, collectively used monthly by 2.7 billion people worldwide.

In an interview with The Washington Post on the eve of the conference, called F8, Zuckerberg said he was still weighing how to respond to criticism and potential regulation, the trade-offs between safety and encryption, and the future of the company’s business. He spoke about reorienting the company’s services toward the fast-growing arenas of private messaging but acknowledged it may be years before these changes are put into operation — and perhaps even longer before people trust those efforts.

“The next five years at least, maybe even the next 10 years, is building out the private platforms with the richness that the public platforms have had to date,” he said. “That needs to get done with some amount of different infrastructure and different policies, and to some degree, different values, than in building out these public spaces.”

Facebook is moving more deliberately now, he said. The “move fast and break things” era is over — replaced by a more cautious approach after crises such as Russian interference, the live-streaming of massacres and suicides, and calls to break up the social network over its lax approach to privacy.

Zuckerberg knows private messaging is capturing a growing share of people’s attention, a motivation for moving the company in that direction. But Facebook still hasn’t figured out how to make money off that behavior. Ninety-nine percent of the company’s revenue comes from targeted advertising, from profiles that are tied to the information the platform collects about people, including what they post publicly on Facebook.

That information — valuable enough to turn Facebook into one of the world’s wealthiest companies — cannot be derived from the new encrypted services Facebook is building because encryption blocks outsiders, including the owners of encrypted services, from reading messages. That reality not only prevents targeted advertising, but also hinders Facebook’s ability to hunt for bad actors such as Russian operatives, Zuckerberg acknowledged. Facebook is the second-largest targeted-advertising company in the world after Google, which reported slowing advertising growth on Monday.

“There’s no way that I can sit here and tell you that we can do 100 percent as well if we eliminate one of the big tools that we have,” he said, referring to the ability to scan messages when the company sees signs of abuse.

Zuckerberg said he didn’t know how much profit Facebook’s new focus on encrypted messaging would generate. But he wasn’t worried. “I don’t know how good of a business it will be, but I am confident it will be good, and we will be fine,” he said in the interview.

Zuckerberg’s comments reflected what has long been a truism about the Internet: Wherever people’s eyeballs go, dollars will follow.

“I think people assume that a lot of the value comes from data,” he said. “What I’ve found is, there’s certainly a reality to that, but I find that in the coverage that’s out there, people underestimate how much of the value is coming from just people’s attention.” His downplaying of data was surprising, given how much Facebook relies on it to power its business.

The tenor of the F8 conference has come to reflect Facebook’s challenges. It is a buzzy gathering of thousands of engineers and other partners who build apps that utilize Facebook’s trove of data for dating services, music recommendations or merely to help their users log in with the company’s ubiquitous “log in with Facebook” buttons. Thousands of people typically fill a large auditorium in San Jose, where they cheer announcements of new partnerships and features about everything from Facebook’s Oculus virtual reality headset to new developments in software infrastructure.

But in recent years, F8 has lost some momentum as Facebook has increasingly restricted developers’ abilities to access data, a result of its shifting business and growing scrutiny of its privacy practices. At the same time, the company’s problems have taken up as much oxygen as any of its product releases. Two years ago, Zuckerberg offered condolences to the family of a man whose murder had been broadcast on the company’s video-streaming platform, Facebook Live. Last year, Zuckerberg announced a privacy tool called Clear History, which still hasn’t launched.

This year, Zuckerberg used his keynote speech to tout the growing focus on private groups and encrypted messages, and he detailed a vision for turning his conglomerate of apps into a single, unified service that is more powerful — though perhaps not more profitable — than each of its parts. Many of these changes are fairly abstract and years away from implementation, Zuckerberg acknowledged.

The most tangible news of F8 will be the cosmetic change to Facebook itself, to “the big blue app,” as it is known within the company. For billions of Facebook users, the quintessential blue bordering on top of the page is as synonymous with Facebook as the “like” button. This is the first major redesign of the app in five years and will roll out on mobile and desktop in the coming weeks.

The color change is part of a redesign that reflects the company’s philosophical shift. News Feed, the scrolling feed of posts that has gotten Facebook into so much trouble with fake news and viral Russian disinformation will still be front and center when a user opens the app. But it is becoming much easier to toggle away from it and move into a different kind of experience, such as a private group. Such groups are one part of Facebook where people are actually spending more time — and still posting the kind of intimate information that few people dare to share publicly as a status update anymore.

And the big blue app — the one Americans and Europeans are increasingly deleting or reducing their use of, according to Facebook’s own numbers — will be less recognizable, a symbol of Facebook’s desire to put on a new face to the world. The redesign cleans up its busy interface with simpler tabs that allow people to quickly navigate to its video entertainment service, Facebook Watch, its Craigslist copycat, Marketplace, and to its private Groups. (Some of these features look a lot like tabs on the home-booking site Airbnb.)

The redesign isn’t a slam dunk. Previous redesigns of tech products provoked backlash, such as when Twitter introduced a new timeline or when Snapchat redesigned its app, particularly from power users of the service.

Instagram, Messenger and WhatsApp are also getting updates. Instagram will make follower counts and “like” counts less prominent — to make the service feel “less pressurized,” according to its head, Adam Mosseri. Messenger will become available on desktop, and people will soon be able to message one another between Facebook’s various apps.

Facebook’s dating service, announced at F8 last year and still in a nascent phase, will add a feature called Secret Crush, in which users can select up to nine friends they are interested in. Facebook will match people if the interest is mutual.

Behind the new face are many pressing questions to which Zuckerberg didn’t have immediate answers. He said he didn’t know whether unifying the company’s services would expose him to more criticism that Facebook should be broken up — calls to do so are being made by Sen. Elizabeth Warren (D-Mass.), a presidential candidate, and others. Nor did he say whether those calls to break up Facebook were the right remedy to its problems.

He pointed out that Facebook’s purchases of WhatsApp and Instagram have given people more variety and choices, not fewer, because the company has turbocharged the growth of those services since they were acquired. Focusing on specific fixes, such as improving the integrity of elections, data portability and privacy were more likely to address people’s “biggest concerns” than breaking up the company, he said.

And there were distinct advantages to Facebook’s size, Zuckerberg pointed out: The amount the company spent on safety last year was greater than the entire revenue of Twitter.

On political microtargeting, Zuckerberg said he had considered getting rid of it entirely. The tools let political advertisers target people by demographics, Zip codes and other interests. They were used by Russian operatives, and critics have said that they allow political actors to exploit people psychologically. Zuckerberg acknowledged the tool caused him headaches but said he ultimately came to the conclusion that they help level the playing field for local politicians and smaller campaigns and were therefore too valuable to scrap.

At least five times in the interview, Zuckerberg said he said he didn’t know or didn’t have an answer to a question — as telling and forthright an acknowledgment of Facebook’s reality as any and an admission of the company’s need to evolve.

Zuckerberg said he didn’t know whether Facebook could do as a good a job policing election integrity or tackling abuse once it could no longer read messages but insisted that consumers would reward privacy in the end. He said he didn’t know whether there was much difference between his vision of privacy and the one Apple chief executive Tim Cook, another Facebook critic, has been espousing for several years. He said he didn’t know whether the encrypted future would be more profitable than the current one.

But, as Zuckerberg said, he is confident all will be fine.