Culture is what people do when no one's watching—and great leaders build it with intention.

In What You Do Is Who You Are, Ben Horowitz explores why culture matters and how to shape it deliberately. The book resonated with me because it articulates something I've observed throughout my career: culture isn't a set of values on a wall. It's the accumulation of behaviors, decisions, and norms that emerge when leadership is—and isn't—paying attention.

What follows are the principles that have stuck with me, along with my interpretation of how to put them into practice.

Create memorable, values-driven rules

Horowitz draws on Toussaint Louverture's transformation of enslaved people in Haiti into an organized, professional revolutionary army—one that would ultimately overthrow French and British colonial forces and end slavery in Haiti forever. The lesson: culture can be forged through deliberate, even surprising, rules that embed values into daily behavior.

Effective culture-shaping rules share a few characteristics:

• They're memorable. The best rules spark conversation. People may not initially agree with them, and that's fine—as long as they're not cruel, confusing, or controlling. They should be bold enough to catch attention and stick in people's minds.

• They invite the question "why?" This isn't about confusion; it's about creating teaching moments. When someone asks why a rule exists and receives a clear answer, the underlying value becomes more deeply understood.

• They're unambiguous. Memorable doesn't mean cryptic. Rules should be easy to understand and follow.

• They're encountered daily. A rule that only applies in rare circumstances won't shape culture. The most effective rules are woven into everyday work.

Dress with intention

I took a professional development class in college where the professor emphasized the importance of dressing well in the professional world. I pushed back—I'd been working as a software engineer and designer in advertising and consulting since I was 16, and tech culture was different. We didn't need suits to be taken seriously.

I still believe that's true. The tech industry genuinely changed expectations around professional attire. But what I've come to appreciate is that how we present ourselves communicates something about the culture we want to create. Dressing for success doesn't mean looking like a runway model. It means being intentional. There's nothing wrong with casual and relaxed—but sloppy or unkempt sends a message too, whether we intend it or not.

Be yourself, but whatever you wear, do it with purpose.

Be authentic—and know yourself

Don't try to be someone you're not. People see through it quickly, and inauthenticity erodes trust faster than almost anything else. Authenticity doesn't mean you can't grow or change—it means staying true to who you are at your core while continuously working to become better.

Self-awareness is the foundation here. Know your strengths. Know your weaknesses. Be honest about both.

Follow a code of honor

Horowitz references the Bushido code, an ancient ethical framework that guided samurai conduct. The principles feel remarkably relevant to modern leadership. As defined by Saitō Chikamori:

• Sincerity — Do not lie. Do not be insincere or superficial.
• Responsibility — Do not be obsequious. Own your work and your decisions.
• Frugality — Do not be greedy.
• Politeness — Do not be rude. Do not slander.
• Modesty — Do not be boastful or arrogant.
• Loyalty — Do not be unfaithful to your commitments.
• Harmony — Maintain good relationships with colleagues.
• Tranquility — Do not be consumed by anxiety over events beyond your control.
• Compassion — Show genuine concern for others. Act with a strong sense of duty.

These aren't just personal virtues—they're cultural building blocks. Leaders who embody them give others permission to do the same.

Be explicit about the behaviors you expect

Saying you want "a culture of integrity" is too vague, even if the meaning seems obvious to you. Integrity means different things to different people. If you want to see specific behaviors—honesty about project status, admitting mistakes early, giving credit to others—name them explicitly. Ambiguity is the enemy of accountability.

Model the behavior you want to see

This should be self-evident, but we often lack the self-awareness to see how our own actions might be encouraging the opposite of what we intend. Leading by example is simple in concept and demanding in practice. It requires becoming the best version of yourself—genuinely embodying the values you want your team to adopt.

When you do this consistently, it becomes contagious. People notice. They respect it. And they start to mirror it.

Make decisions that demonstrate priorities

This is another form of leading by example, but it applies specifically to strategic choices. Where you allocate resources, which projects you prioritize, how you respond to tradeoffs—these decisions communicate what actually matters, regardless of what your stated values say. Alignment between words and actions is everything.

Hire for the culture you want

When building a team, think carefully about the qualities that matter most. In my experience, the people who elevate culture tend to share certain traits:

• Intellectually curious — Smart and genuinely eager to learn.
• Humble — Focused on the work, not on personal recognition. The kind of person others want to collaborate with.
• Driven — Hardworking, competitive in the best sense, and determined to see things through.
• Collaborative — Willing to lead when needed, and equally willing to support others and take responsibility for shared outcomes.

Protect the culture by addressing misaligned behaviors early

When you're working hard to cultivate certain values, you have to be vigilant about patterns that undermine them. Allowing those patterns to persist is implicit endorsement, whether you intend it that way or not. Address issues proactively—and if coaching doesn't lead to change, protecting the broader culture sometimes requires difficult decisions.

A few behavioral patterns that consistently erode culture:

• The Chronic Critic — Finds faults in the organization and spreads negativity to others. There's a difference between raising legitimate concerns with the intent to solve them, and simply stoking outrage. The former builds trust; the latter poisons it. Address this pattern immediately.

• The Inconsistent Performer — Talented but unreliable. We've all worked with someone like this—perhaps we've been this person at times. They can deliver excellent work, but lack the discipline, focus, or follow-through to do so consistently. Potential without reliability doesn't build trust.

• The Poor Communicator — Struggles to give or receive feedback constructively. Often dismissive of criticism, which makes improvement nearly impossible and collaboration frustrating for everyone else.

• The Fear-Based Motivator — May be excellent at their craft, but relies heavily on anger, shame, or guilt to drive results. This approach might produce short-term outcomes, but it's unsustainable. It leads to burnout, resentment, and eroded trust over time.

Culture comes down to people and their actions

A company is only as good as its culture, and culture is only as good as the people who live it every day. This is simple to understand and challenging to maintain. But the principles above provide a foundation—for building something worth being part of, and for leading in a way that brings out the best in the people around you.