This rogue hacker digs up unreleased features on Instagram, Facebook, and Spotify - and she often finds out about them before other employees at those companies do

• Jane Manchun Wong is a Hong Kong-based hacker who discovers unreleased features on apps for fun.
• Wong has gained a following by revealing new features on Instagram, Spotify, Facebook, Lyft, and other apps months before they were officially announced.
• She uncovered Instagram's experiment with hiding likes weeks before the company announced it - and an Instagram employee said her Twitter feed is more informative than the company's internal comms.
• Visit Business Insider's homepage for more stories.

As Jane Manchun Wong was digging through the code of the Instagram app after a recent update, the 25-year-old noticed something unusual - a new, experimental feature built into the code was named, "What's up Jane."

The Hong Kong-based software developer doesn't work for Instagram, or any other major app. But she's built a following among tech workers, journalists, and enthusiasts because of her penchant for digging up and publicizing unreleased features long before they're officially announced.

Wong did what she normally does when she discovers something new in an app's code: she tweeted about it. Later that day, Instagram CEO Adam Mosseri seemed to confirm the Easter egg.

Wong said in an interview with Business Insider that she first started seeking out apps' experimental features for fun.

"I guess it's just my curiosity that drives me," she said. "To me, this is a puzzle and I have to solve it."

Wong first began digging into apps' code years ago, driven by a desire to understand what companies meant when they vaguely described app updates as "bug fixes and improvements." Whenever an app is updated, Wong extricates the code, seeking out dormant bits that may indicate a feature that's being tested. Then, she reverse engineers it to make the hidden feature show up on her phone.

She regularly predicts features weeks or months before they're officially announced by apps like Facebook, Instagram, Spotify, and Lyft. She's racked up more than 60,000 Twitter followers in the process, and her work has been featured in CNN Business, CNBC, and the BBC.

Wong was the first to report on Instagram's controversial experiment with hiding likes, revealing the feature two weeks before Instagram began publicly testing it.

Wong occasionally makes money by reporting security flaws to companies' bug bounty programs, but otherwise does her sleuthing purely as a form of leisure. However, she says she's open to working as a developer for a major platform, "if they'll have me."

"I mostly just like to know how the apps work underneath, and how they're structured," she said. "Now I share it on Twitter because people apparently do find it interesting. So, why not share it with the world?"

Here are some of the high-profile features Wong predicted correctly, as well as some new features she's spotted that are still unconfirmed.