Most fintech tools weren’t built for your local auto shop. Affiniti is changing that. Founded in 2021 by Aaron Bai and Sahil Phadnis while they were students at UC Berkeley, the startup aims to become the financial brain for small and medium-sized businesses.

From Expenses to Intelligent Finance

Affiniti began by launching an expense management tool and a small business credit card in late 2024. These products weren’t designed for startups or tech companies, but for everyday businesses like HVAC companies, independent pharmacies, and auto dealerships. The goal was to help business owners manage spending, track expenses, and streamline reimbursements without relying on tools built for a different type of user.

The team has since expanded its ambition. Affiniti is building “AI CFO” agents; industry-specific financial tools that automate and manage banking, bill payments, sales analytics, cash flow insights, and more. Instead of being a generic assistant, each AI agent is tailored for a particular vertical, making financial intelligence more useful and accessible for busy operators.

Rapid Growth and Strong Investor Backing

In May 2025, Affiniti raised $17 million in a Series A round. This came only six months after an $11 million seed round, bringing its total funding to $28 million. Investors included SignalFire, Contrarian Thinking Capital, Sequel, Indicator Ventures, and several notable angels.

This new capital is being used to expand the platform’s features; building in banking services, deeper analytics, and integrations with systems like ERPs and point-of-sale tools. The speed of the company’s fundraising reflects both strong investor belief and a clear product-market fit in an underserved segment.

Going Deep with Industry Trust

Affiniti’s growth strategy isn’t just about tech. The founders have placed heavy emphasis on building credibility within the industries they serve. That includes partnering with trade groups for verticals like independent pharmacies. These partnerships help validate Affiniti’s offering and allow for bundled benefits, such as group purchasing discounts, which make the financial platform even more attractive.

“We want to be their full financial operating system over time, because we have the advantage of being the first fintech they’ve ever used.”

— Aaron Bai, Co-founder of Affiniti 

In just over a year, Affiniti has grown to 1,800 business customers and is processing $20 million in monthly transaction volume. It expects to cross $1 billion in total volume by the end of 2025.

Key takeaways for fintech startups

Here’s what fintech startups should take away from this:

• Focus on real-world business needs. Affiniti built tools for businesses often overlooked by fintechs
  
  
• Customize your product for the user, not just the sector. AI CFOs tailored to specific verticals offer more value than one-size-fits-all tools
  
  
• Strategic partnerships can unlock access and trust faster than broad marketing
  
  
• Fast, focused execution helped Affiniti raise two rounds in six months

Conclusion

Affiniti shows that there’s massive potential in building for the backbone of the economy. By combining tailored AI with deep industry insight, it is redefining what financial management looks like for small business.

If your fintech startup is looking to do the same, we can help you craft the strategy to get there. Let’s talk.