PRECISION, GRIT, & THE PERFECT ENTRY: Building a Startup Like a Championship Diver

Featuring Marcus Rien, Founder of Waves CPAs

When most people talk about making the leap from corporate to startup, they don’t know what it’s like to take a literal leap. But Marcus Rien isn’t most people.

A former competitive diver, current scratch golfer, CPA, CFO, and now founder of Waves CPAs, Marcus spent years building back offices and advising fast-growing companies. Over time, he realized the entire financial talent system was too rigid, too expensive, and too slow to meet the needs of modern businesses.

So he built something better.

Listen to the full episode here

From Big Firm to Big Ideas

Marcus started his career in private accounting and financial analysis. He also worked on mergers and acquisitions, risk management, and systems implementation. Then he transitioned into public accounting at the fifth-largest CPA firm in the world. There, he gained deep insight into how the profession operates. That experience led him to join a client company as an internal controller, where he built their entire back office from scratch.

It was a renewable energy startup backed by private equity, and the capital gave him room to do things right.

This was where the idea for Waves CPAs started to take root. He saw how difficult it was for companies to find the right financial talent at the right time and how rigid the traditional hiring and consulting models could be.

What Is Waves CPAs?

Waves CPAs is a platform that connects businesses with entrepreneurial CPAs. These CPAs work as independent contractors and have the ultimate flexibility. They can choose which clients to work with, whether they want to work remotely or in person, and how many hours they want to commit.

Contracts are clearly defined with start and end dates, allowing CPAs to scale up or down based on their schedule or seasonal availability.

Businesses benefit too. Instead of hiring a full-time financial leader they might not need year-round, they get fractional access to a seasoned CPA who can drive value right away without the overhead. This model is flexible, scalable, and well-suited to the changing needs of modern business.

Why the Traditional CPA Model Falls Short

Hiring a full-time CPA is tough. For one, there are only about 670,000 CPAs in the U.S., and many are already dedicated to tax and audit work. That leaves a limited pool of professionals available for internal finance roles.

Even when companies do manage to hire, they often realize their teams aren't operating at full capacity. Many W-2 employees are completing 20 to 24 hours of true work per week. So why pay for 40?

Marcus believes fractional finance is a smarter alternative.

With Waves CPAs, companies can:

• Get the right expertise without overcommitting on salary.

• Align financial support with actual business needs.

• Tap into experienced professionals who want to work with intention and purpose.

This model also opens up career opportunities for CPAs who want more autonomy, variety, and control.

The First Use Case: Himself

Marcus was the first test case for Waves. As the original entrepreneurial CPA on the platform, he built his own book of fractional work to validate the model.

He found real advantages:

1. He could choose the clients and industries that mattered to him.

2. He was no longer tied to a single employer or income stream. Instead, he diversified his workload and found greater financial stability.

3. He also loved the variety, as each client brought new challenges and learning opportunities.

This autonomy was energizing. He was learning, growing, and helping businesses in ways they couldn’t have accessed otherwise. And it gave him the confidence to go all in on building the platform.

Founder Life: Year One Lessons

Becoming a tech founder wasn’t exactly smooth sailing. The first nine months were intense. Every day brought new problems, from product decisions to resource gaps to messaging challenges. And because the company is product-led, building the tech right was a constant priority.

Marcus had to guide his team to focus on simplicity and speed. Get the platform functional. Solve the main use cases. Let real-world feedback guide the roadmap. As he puts it, you need to hit 80 percent of what users need; perfection isn’t realistic in tech.

This mindset of progress over perfection kept them moving forward, even when the to-do list felt overwhelming.

Advice for Founders: Be Persistent. Let Go of Perfect.

Waves CPAs is the first tech company that Marcus founded, and he's learned many lessons along the way. Marcus offers a few pieces of advice to other founders:

First, persistence wins. There will be moments where giving up seems logical. But if you push through, reflect, and remember why you started, that clarity becomes your fuel.

Second, perfection is a trap. While it can be tempting to put off the launch of a product until everything seems "perfect" that mindset will slow you down and make it so you may never take the leap.

One of Marcus’s favorite sayings is, “Every day better than the last.” You won’t win every day. Some days will be duds. But if you commit to showing up, listening to feedback, and adjusting with grace, you’ll keep improving.

He credits much of this mindset to his background in competitive sports. As a competitive springboard diver and golfer, he learned to prepare, go for it (the dive, the chip), and if the outcome isn't ideal, stay curious, and move on from failure. Every bad shot or missed dive is just a new opportunity to problem-solve creatively and get better over time. Entrepreneurship, he says, is exactly the same.

Community and Growth: Why Feedback Matters

Building a startup can be lonely, especially when working remotely. But Marcus leans into community and mentorship to stay grounded. He pulls advice from past colleagues, current mentors, and new voices in his space.

More importantly, he seeks out honest feedback. It’s easy to be surrounded by "yes-people". But progress comes from truth, even when it stings. Marcus encourages all founders to find people who will challenge them, ask hard questions, and keep their vision sharp.

Sales, Marketing, and Building a Marketplace Startup

Despite not coming from a traditional sales background, Marcus has embraced founder-led sales. He’s leaning on his network for warm intros and learning how to market the business across LinkedIn, Instagram, and even Twitter.

Waves CPAs is a marketplace, which means business development is needed on two sides... the supply (CPAs) and demand (companies) ...simultaneously. That requires balance, patience, and a clear understanding of what each side needs most.

He’s focused on keeping both sides growing together, with thoughtful matching and responsive product development based on real client and CPA feedback.

What’s Next for Waves CPAs?

This summer, the Waves team is focused on two big efforts: community building and client acquisition.

They attended AICPA Engage, the largest CPA conference in the U.S., to connect with professionals and raise awareness. Then Marcus will shift his focus to finding more small and midsize businesses that need fractional financial support.

He’s also exploring enterprise opportunities with Minnesota’s many Fortune 500 companies and building partnerships with CPA firms that need independent contractors for overflow or restricted work.

It’s a busy, exciting time, and Marcus is ready for it.

Smart Growth Needs Smart Finance

If you’re a business leader who needs financial expertise but can’t afford (or don’t need) a full-time controller or CFO, Waves CPAs is worth a look. And if you’re a CPA tired of the traditional firm grind, Marcus built this for you too.

Smart growth starts with curiosity. And Waves CPAs is making it easier than ever to find the finance support you need to grow well.

Explore Waves CPAs at https://wavescpas.com/  or connect with Marcus on LinkedIn. He’ll probably respond faster than your old firm ever did.