Apeksha Kothari is a second-year student who spent her summer at www.RareCarat.com, a start-up that guides consumers on where to buy their diamond engagement ring. She will be heading back post-graduation as their Chief Operating Officer. Here, she reflects on her experience making the choice to join a start-up and the lessons she learned.

1. No pressure, no diamonds.
In the cash-strapped environment of a start-up there is pressure to deliver direct results; there's no hiding behind the delayed consequences and layers of management of a bigger company. As my start-up warned when launching a new feature, "If it doesn't work, we can always blame Apeksha". It can be a stressful environment to walk into full-time. However, the MBA summer internship provides a unique opportunity to reduce the risk on both sides, allowing to test for compatibility and value-add.

2. Be fearless.
My favorite customer research call began with a pointed, "Aren't you guys killing my business? Why should I even be taking this call right now?" He's now on our advisory board. Going through the HBS Start-up Bootcamp prepared me for situations like these. It's fine if 99 people say no, as long as one says yes. It's okay not to be liked, it's okay to feel awkward, and it's okay to roll with the punches until something works.

3. Passion matters.
"Do what you love" has always felt like a millennial myth. But, building a business in an industry I'm passionate about has broken the cynic in me. I'm part of the fifth generation in my family to work in the diamond industry, and while it's an exciting industry, it is also one of the slowest to adapt and innovate. Working on a way to bring it into the 21st century is like living a case study, and incredibly exciting.

4. Big problems are daunting. Small problems are addressable.
We all know we're in a changing world. The rules of competition are in flux as artificial intelligence, big data, and changing consumer preferences come into play. It's huge, scary and hard to see the forest for the trees. But rather than make generalizations on these macro-trends and think top-down, HBS classes like The Entrepreneurial Manager train us to think bottom-up. We learn how to test hypotheses quickly, and how to use new tools to solve old problems.

5. Skills are transferable.
I came from the retail and manufacturing world, and was apprehensive about going into a tech-heavy environment, but there are many surprising parallels. One that stands out: I previously worked at a luxury diamond jeweler. We obsessed about the customer and focused relentlessly on getting every tiny detail right for beautifully crafted jewelry. A couple of weeks into my internship, I was working on product design for the website: same principles and same customer focus.

6. Personality matters.
Entrepreneurial environments are not for everyone, but HBS has helped me understand that it is for me. Going through hundreds of business problems helped me find my voice and discover where I wanted to contribute to the conversation. For me, this was the thrill of the uncertain, where I could run off into a world full of 'what if…?' Turns out that's a personality fit for entrepreneurship

7. My choices are excellent data points for understanding myself.
Being on a campus with an absolute smorgasbord of options is overwhelming. But the environment forced me to start saying no to a lot. And seeing where I was saying no helped me understand the moments where I said yes, making me sure about the path I'm taking.

8. It's chaotic. Adapt.
I joined in business development, but it was clear from day one that I needed to ignore any possible scope of responsibility that the title implied and get my hands into whatever needed to get done. In fact, Professor Jeff Bussgang goes as far as recommending eliminating titles at a start-up. Which brings me to my next point...

9. I am going to fail at something and that's okay.
In an early-stage start-up, I am a generalist, not a specialist, and in the range of things I work on, there are definitely a couple things that I won't be great at. Or, with the time crunch and brutal prioritization necessary, some outcomes are going to be disappointing. But team-based learning like Field Global Immersion force close collaboration and honest peer feedback, and has helped teach me how to manage shortcomings in a mature and constructive way. 

10. And finally, "Don't do it."
I asked Ajay (www.RareCarat.com's CEO) for advice to budding founders and joiners. He said it's simple: "Don't do it." He was joking, but this is actually the perfect test: are you so passionate and eager to run your own race that you can ignore everyone that says "Don't do it?" …Then do it.