As companies grow up, their branding usually does, too. That often means that the initial quirkiness of a startup logo fades into the slick, streamlined branding you see everywhere today–like that same sans serif font that has become the basis for Google, Airbnb, and Pinterest’s wordmarks .

The marketing company Mailchimp, which today is announcing a complete rebrand, could have easily given up the quirkiness that defined its branding as a young company the way many other giants have. Instead, with the help of branding agency Collins, Mailchimp is doubling down. It’s keeping its logo-cum-mascot Freddie the Chimp, for starters, and using an analog typeface from the 1920s as its new typeface, and illustrating its new brand with a series of almost childlike drawings that look unpolished and rough by design. Weird branding is alive and well in the tech industry.

Mailchimp itself was responsible for pioneering the kind of friendly, humorous design you see everywhere in tech nowadays, which was radical when the company first launched in 2001. Perhaps most emblematic are the company’s ubiquitous podcast commercials, which poked fun at its name: “Mail . . . kimp?” It’s hard to imagine Google making fun of its own name in commercials. But that was Mailchimp, with its primate logo and curly, seemingly handwritten wordmark.

“That wry sense of humor is an authentic part of their brand,” says Ben Crick, a creative director at Collins who worked on the branding. “They have more of a right to it than most of the tech companies that rely on humor.”

That winking humor, along with playful illustrations that are meant to demystify what a tech company does, is commonplace among startups these days. “It’s the de facto way to look if you’re a tech company,” says Angie Shih, a strategist at Collins. “The trajectory of every company is that you’re quirky, friendly, approachable, and when you become a massive company with a lot of employees, you become austere, sterile.”

Mailchimp wanted to keep its quirk and eschew the traditional logo trajectory that Shih references, where large tech companies opt for the slick and seamless over the human. But the company did want to rebrand for similar reasons that others do: It has grown significantly since its founding 17 years ago. The company sends about a billion emails per day, and as of 2017, it was adding 14,000 new customers per day.

“As we evolve as a company and are offering these different services and features, we need to evolve our brand and our visual language as well,” Gene Lee, Mailchimp’s vice president of design, tells Fast Company. Features now include marketing automation software that’s more sophisticated than the email building software that the company has been known for.