By Adam Mendler, CEO of The Veloz Group and founder of Beverly Hills Chairs, Custom Tobacco and Veloz Solutions.

The pandemic has tested businesses of all sizes across industries in different ways. While I have spoken to many leaders about their best advice about how to lead during times of crisis, uncertainty and change, my entrepreneurial experience since the onset of the pandemic has been as good an educator as any.

My team and I have been operating Beverly Hills Chairs for almost a decade. We sell refurbished brand-name office chairs at discounted pricing, and since the business's inception, we have primarily catered to a core customer group: small- to medium-sized business owners. When the pandemic hit, we were faced with a big problem: Our customer base disappeared overnight. The small-to-medium-sized business market that was central to our existence suddenly vanished with offices closed indefinitely, and in turn, our ability to sell to offices went away for the foreseeable future.

Prior to the pandemic, a much smaller share of our business had been selling to those working from home offices, but as remote work swept the nation, we immediately pivoted our business and focused exclusively on catering to the home office market. This meant making a number of operational changes to our business. For example, when selling chairs to small businesses, a company might order 50 chairs to fill out or augment its office, whereas in the home office market, selling 50 chairs entails selling to 50 individual customers. In response, we had to scale our customer service and warehouse teams, but we did not divert focus on who our new customer was. We remained as devoted to meeting the needs of each individual in search of the right chair for their home offices as we were to meeting the needs of an office manager -- who wrote much larger checks.

Despite the challenges of the pandemic, we managed to make it through. Here are three entrepreneurial lessons I learned from this experience: 

1. Be nimble, flexible and responsive to the needs and wants of the market.

We couldn't wish our old customer base back into existence. We had to adapt to the new market dynamics and focus on the customers who had demand for what we sold. We also had to make adjustments to our pricing, marketing, warehouse operations and staffing throughout the pandemic.

Entrepreneurs need to be open to making changes at all times, recognizing that what worked yesterday might not work today or tomorrow. Flexibility starts at the top but must permeate throughout your organization. Not only must leaders be responsive to change, but leaders must create and foster organizational cultures that engender adaptivity.

2. Apply the same principles that appealed to old customers when cultivating relationships with new ones.

As important as it is for businesses to pivot, entrepreneurs should not lose sight of the underlying principles to succeeding in both good and bad times, starting with customer-centricity. Even when shifting focus to a new audience, continue to prioritize customer service and the customer experience. Ensure that you are delivering a best-in-class customer service experience by communicating clearly, proactively and honestly at all times. Refuse to compromise on quality, no matter the external circumstances. Offer a great value proposition, even if it is not the lowest cost option.

3. Understand what you can and can't control.

The pandemic underscored a lesson entrepreneurs need to be reminded of from time to time: There is only so much within our control. Just as we can't control whether there will be a global health crisis, we can't control the broader market conditions impacting our businesses. We can control our mindsets, our attitudes, how we spend our time, who decide to surround ourselves with and how we operate in times good and bad. We can also control what we can focus on -- and that should be what is within our control.