St. Augustine, Florida
Accounting and financial analysis, done by the people who show up to your meetings.
A licensed CPA, an accountant, and an analytics principal — audits, bookkeeping, FP&A, and Florida community association compliance, under one small firm instead of one overworked senior.
What we do
FP&A & financial systems
Financial modeling, reporting rebuilds, and process automation — the discipline of making a finance function run on its own systems instead of tribal knowledge.
Learn more →Audits, reviews & compilations
Attest engagements performed under Mike's Florida CPA license, at the level a client actually needs — not upsold past it.
Bookkeeping & accounting
Ongoing books, reconciliations, and financial statement preparation for businesses and associations that need accurate numbers without a full-time controller.
Community association compliance
Florida HOA and condo financial reporting — audits, reviews, and compilations at the statutory tier your association actually owes.
Learn more →Who we are
Three principals, and the one who does your work is the one you meet.
Mike O'Donnell, CPA
Owner — Attest, Tax & Assurance
Mike owns DSDT Financial and signs the firm's attest work. He spent five years in audit and assurance in public accounting, at two established firms, before moving into industry finance leadership. He has since run accounting for a multibillion-dollar global manufacturer as an Assistant Controller, directed finance and accounting for a regional hospital system, and has served as Vice President of Finance for a growth-stage technology company since 2022. He holds an MS in Accounting and Finance from the University of Cincinnati's Lindner College of Business and a BA in Economics from Denison University. FL CPA license #AC52814.
- Audits, reviews & compilations
- Tax
- Engagement quality
Joseph Cox
Accounting & Bookkeeping
Joe has spent more than a decade in accounting across government, healthcare, and transportation — currently as a Senior Accountant for a Florida municipal government, where he prepares the worksheets that carry the city through its annual audit. He has supported audits from the inside at a regional hospital system and a regional transportation authority, and has run grants accounting, fixed assets, and balance sheet reconciliations at each. He holds a degree in Accounting and Forensic Accounting from Franklin University.
- Bookkeeping
- Fixed assets & reserves
- Audit readiness
Brent Tantillo, PMP
FP&A, Analytics & Technology
Brent builds the financial models, reporting, and systems automation behind the work. As a Senior Financial Systems Analyst for a large Florida nonprofit, he documents and rebuilds finance workflows against state-mandated deadlines, and he has built cash flow and revenue models that helped businesses secure millions of dollars in financing. He holds an MBA in Business Analytics from Florida Atlantic University, a JD from the University of Houston Law Center, and a BBA in Finance from the University of Texas at Austin. He works in SQL, Python, Power BI, and Tableau, and he is PMP certified.
- FP&A & financial systems
- Board & trend reporting
- Automation
Get in touch
Tell us what you're working with — a business that needs its books rebuilt, an association that needs an audit, or a finance function that needs automation — and we'll tell you what it takes.