Sheryl Sandberg vs. Eric Ries: Battle of the Leans

Lean In vs Lean Startup

Failure.

Something we all face.

But what do you do when you fail?

Today’s two books, Lean Startup and Lean In, try to give you the answers. They both came out of Silicon Valley in the 2010s. They both started world-changing movements, and redefined the cultures of businesses, careers, and lives. And they did so from completely opposite angles.

I’ve been looking forward to this battle for a long time. Because this is not just observational, but personal. In fact, I built my business around one of these books’ philosophies and lived to tell the tale.

Let’s get our “Battle of the Leans” started.

Eric Ries

A software engineer who cofounded a Silicon Valley company and failed miserably, because he spent months building features nobody wanted, and launched to a world that didn’t care. So instead of stress-eating Korean hot chili noodles (my #1 go-to), he started a blog (my #2 go-to), and documented his learning from failure. The blog became a book, a movement, a rewiring of an entire generation of startup founders’ brains.

The Lean Startup (2011)

This book thinks your business plan is a fantasy. It doesn’t matter how smart you are or how good your idea sounds. Until real customers touch your product, you’re just guessing. Ries argues that every startup is essentially a series of experiments, not the execution of a master plan. The goal isn’t to build the perfect product. It’s to learn what customers actually want as fast and cheaply as possible, then iterate. The companies that win aren’t the ones with the best ideas. They’re the ones that learn the fastest.

Core Ideas:

• Build-Measure-Learn. This is the core loop. Build a minimum viable product, measure how customers respond with real data, learn, then repeat. Speed of learning is everything.

• Minimum Viable Product (MVP). Don’t build the full thing. Build the smallest and cheapest possible version that lets you test your core assumption.

• Validated learning over vanity metrics. Likes, page views, and total signups feel good but tell you nothing. The only metrics that matter are the ones that prove customers will actually pay for, use, and come back to your product.

• Pivot or persevere. When the data says your idea isn’t working, you have two choices: pivot (change direction based on what you learned) or persevere (stay the course because the data is promising).

• Innovation accounting. Traditional accounting measures revenue and profit. Startups need a different scorecard: learning velocity. Are you getting closer to product-market fit? Are your experiments producing clearer answers?

This book became Bible in Silicon Valley in the 2010s. Before this book, “lean” was a term reserved for the Costco meat section. After it, it became a goal for every startup. Its ideas (especially the terms “MVP,” “pivoting,” “product-market fit”) are so overused that the book feels dated today, kind of like watching the 1995 movie The Net (starring Sandra Bullock) in 2026.

Sheryl Sandberg

Sheryl Sandberg was the kind of overachiever that makes all overachievers feel like failures. Harvard undergrad then MBA, Chief of Staff at the US Treasury Department, VP at Google where she built the ad sales team, then COO of Facebook where she turned a zero-revenue startup into one of the most profitable companies in history. She was one of the most powerful women in corporate America, but noticed that there weren’t many other women in the room with her. That observation became the book.

Lean In (2013)

This book thinks women are being held back by two forces: external barriers that everyone acknowledges and internal barriers that nobody talks about. Sandberg argues that women pull back from their ambitions before they need to, don’t negotiate hard enough, don’t raise their hands, and shrink themselves in rooms full of men. The solution: lean in. Take the seat at the table. Raise your hand. Don’t leave before you leave.

Core Ideas:

• Sit at the table. Women routinely take peripheral seats in meetings, defer to others, and diminish their own contributions. Sandberg says be there, speak up, and act like you belong, because you do.

• Don’t leave before you leave. Women start pulling back from their careers in anticipation of having kids by turning down promotions and stopping raising their hands years before necessary. By the time the baby arrives, they have voluntarily opted out of crucial opportunities.

• Make your partner a real partner. Equal careers require equal partnerships at home. Negotiating the home workload is as important as negotiating your salary.

• Seek mentors, but don’t make it weird. Mentorship happens naturally through excellent work and relationship building. Earn it, don’t ask for it.

• Own your success. Women attribute their achievements to luck, help from others, or timing. Men attribute theirs to skill. Sandberg says stop apologizing for being good at what you do.

The book started as a cultural earthquake but drew massive backlash in the #MeToo and anti-grind era. People said a billionaire telling regular women to just try harder was tone-deaf to the systemic problems of childcare, pay gaps, and workplace discrimination that individual ambition can’t fix.

Comparison

They both have “Lean” in the title and mean the complete opposite thing by it.

Eric Ries says: don’t commit. Test. Hedge. Build the smallest possible version of your idea, measure whether anyone cares, and be ready to pivot the moment the data says you’re wrong. Your instincts are probably wrong. Your passion for your idea is a liability. Kill your ego and listen to the customer.

Sheryl Sandberg says: stop hedging. Commit. Lean in. Raise your hand. Your problem isn’t that your idea is wrong. It’s that you’re not backing yourself hard enough. Self-doubt is the enemy. The data you need is already inside you. You’re just too afraid to act on it.

Ries says your conviction will get you killed.

Sandberg says your hesitation already is.

Are you failing because you’re not testing enough or because you’re not believing in yourself enough? Do you need less ego or more? Should you listen to the market or listen to yourself?

And the beautiful irony: Ries built his framework after his company failed because he was too committed to his original vision. Sandberg built hers after watching women fail because they weren’t committed enough to their own ambitions. They both diagnosed the same symptom (people not succeeding) and prescribed opposite medicine.

Whose idea helped you more? The vote is yours!

My Vote

As I mentioned at the beginning of the article, this battle is personal. In 2012, I read Lean Startup and decided to quit my job and start my company, because with this manual, there was no way I could fail.

Well fail I did. I followed the book step-by-step, but nothing worked. Looking back, the idea that you can iterate your way out of any bad idea was not only intoxicating, it was damaging.

It made me and my team doubt every decision. Anything that didn’t go our way was a signal that we made a bad assumption. Every idea was half-baked and ended with conversations of “let’s test them out.”

Our lives became daily throwing-shit-against-the-wall-and-see-what-data-say. We usually had no data. And in rare cases that we did, the data always said “shit #1, shit #2, and shit #3 were all shit.”

And this way of running a business even spread into my personal life. I became a hedging maniac. Couldn’t commit to anything and looked to A/B test everything, including ways to wipe with toilet paper. It was an agonizing way to live, sometimes literally.

It wasn’t until I decided to take on the 100 Days of Rejection project that I made a mental shift. The idea of doing things for “100 days” regardless of what data might say was liberating, because the inherent commitment of that 100 days pushed me through all the doubts and hedging tendencies. When I had no results or “data” at the beginning, I couldn’t care less because I had 97 more days to go. Better get on it.

Today, my life philosophy can be summed up in three words:

Convictions with a Deadline.

I think through and carefully design my projects, execute with 100% intensity, then move on when it’s over. No daily pivoting.

I am not criticizing Lean Startup. It has made a lot of successful founders. But because I’ve personally witnessed its mental side effect, and because I live a very different life now, I can’t in good conscience vote for the book.

My vote goes to Lean In.

But if you’ve lived through Lean In and were traumatized, let me know.