Have you ever wondered what it would be like to work in the upper echelons of Silicon Valley giants Google and Apple? Both are close-mouthed about their inner workings, and Google goes so far as to require that employees sign a wide-ranging confidentiality waiver that bars them from discussing any aspect of working at the company with anyone, or even publishing a novel about working at a Silicon Valley company without first letting the company review it.

But in an interview at the recent Qualtrics Insight Summit, Kim Scott, the bestselling author of Radical Candor: Be a Kickass Boss Without Losing Your Humanity, reveals what it's really like to be an exec at Apple and Google. Before she became an author and CEO coach, Scott created the "Managing at Apple" course at Apple University, and before that, she led AdSense and YouTube at Google.

Here are her observations about how the two workplaces differ:

1. Apple is all about control.

You can see it very clearly in the way the company serves you lunch, Scott says. "If you go to lunch at Apple, the Caffe Macs (as Apple's eateries are called) make you these beautiful meals, fully composed, the starch with the protein with the vegetable, and they are elegantly served. It's like going to a really nice restaurant." And, like Apple products themselves, the food service is "vertically integrated," Scott says. For example, Caffe Macs contracts with its own fishermen. "They don't want to poison the brains of these people whose brains they are paying for," Scott says. And, of course, you have to pay for the food; it isn't free.

Similarly, at both Google and Apple, employees routinely use bicycles to get where they're going, a highly logical approach since the weather in Silicon Valley is usually beautiful, the campuses are spread out (Scott once found herself working two miles away from her immediate supervisor) and parking is extremely difficult. Both companies provide bikes for employees to use, and Apple's are all identical and beautiful: silver with a black seat and red bell. Bikes are hung neatly in bike rooms.

2. Google is all about inclusion.

Compare that approach to Google's, where, Scott says, "There are no bike rooms. Bikes are everywhere. They're multicolored. A third of them are broken. But it's kind of fun and jolly."

In the cafeterias, she adds, the food is free and tends towards the eclectic. "It's kind of like a smorgasbord," she says. "It's all delicious, all organic, all wonderful. But I'd wind up with a plate full of food and none of it quite went together."

Which approach works better? There's no simple answer. "I love both companies," Scott says. "I'm probably more Googly in my heart of hearts than I am Apple. But I'd rather buy an iPhone than an Android phone, and I'd rather eat lunch at Apple than at Google."

3. At Google, the default answer is yes.

The cafeterias and the bike rooms represent two very different approaches to innovation, Scott adds. "If you wanted to get something done at Google, you didn't have to ask permission. You would just start telling people you were doing it and start doing it. So there's sort of a consensus-based, fast-moving culture--which I would have said was impossible before I joined Google."

It worked, she says, because Google has what she calls "a bias to yes." With that culture in place, "You could do something, and eventually if someone wanted to stop you they could exert the energy to stop you. In other words, you had to exert energy to stop someone from doing something. You didn't have to exert energy to start."

That culture didn't arise by accident, Scott adds. It was likely the result of a frustrating summer job Google co-founder Larry Page once described to her. "His boss explained the project, and Larry had an idea to accomplish everything he was supposed to accomplish over the whole summer in something like half a day. And his boss said, 'No, no, no, you can't do it that way, you have to do it the way we've always done it.' And he was miserable and frustrated. We've all been there. He looked right at me and said, 'I never want anyone at Google to have that experience, ever.' And Google did a huge number of things to make sure there wasn't that sort of wing clipping."

The fact that this culture remained as the company grew is a testament to Marissa Mayer's leadership, Scott says. "There was a point when the company was growing and, as she put it, the goalies had gotten too good. The naysayers were stopping things from happening and it was too hard to do stuff." And so Mayer made some changes. For instance, engineers were told they could run experiments on a certain percentage of users at will, without getting permission first. "Sometimes these experiments would have noticeable impacts on revenue," Scott says. "They drove Sales crazy! But it was very important as part of the culture."

4. At Apple, the default answer is no. But if they say yes, they give you everything you need to succeed.

One of her Apple colleagues told Scott that, when new hires arrived, he would show them two folders, his "yes" folder and his "no" folder. The "yes" folder has about four pages in it; the "no" folder had thousands of pages in it. "And the name of the game at Apple was not to get discouraged by the nos and keep pushing," Scott says.

Because, if you could persuade your boss and your boss's boss to say yes, "the resources flowed," she recalls. "When I got to Apple to design this class in managing, I was given five months to do nothing but design the class. If I had designed a managing class at Google, I wouldn't have been given a minute." (The company's legendary 20 percent time for your own projects existed in "the fantasy Google, not the real Google," she says.)

At Google, she says, she probably would have wound up designing the class between 10 pm and 3 am on the night before she gave it, she says. "Apple cleared my decks and didn't ask me to do anything but design this class. That was amazing. You were expected to go deep and perfect things."

That experience served her well when she set out to write Radical Candor, she adds. "I think my instinct is much more like Google--launch and then iterate. But I couldn't have finished the book if I hadn't worked at Apple. I learned a lot about the value of wrestling with one word for weeks at a time. I really does make a difference."