A small team with big ideas.

Joe Schilz, CPA

CPA · Founder

Joe has spent his entire professional career in accounting, establishing the practice in 1987 after four years as an auditor for the Wisconsin Department of Revenue. A Muskego native, he earned his Bachelor of Business Administration in Accounting from UW-Whitewater in 1983. Joe and his wife Jackie have three daughters: Gina, Abby, and Josie.

Nick Johnson, EA

EA

Nick specializes in individual and business tax preparation. He earned his Bachelor of Business Administration in Accounting from UW-Whitewater and his M.B.A. from UW-Parkside, and he is also a fully licensed Financial Advisor. He helps business owners set up employer-sponsored retirement plans and guides individuals planning for their financial future and retirement, believing tax planning and financial planning go hand in hand. Outside the office, Nick and his family are always on the go, whether trying new restaurants, taking spontaneous road trips, or checking things off the bucket list.

Kathy Rendflesh

Kathy lives in South Milwaukee with her husband, Wayne. They have two grown daughters in the Milwaukee area. Kathy enjoys spending time with family and friends.

Brian Dziak, CPA

CPA

Brian is a long-time team member who joined in 1993 after earning his Bachelor of Science in Accountancy from Marquette University in 1991. A business expert, he specializes in management consulting and tax planning for small-to-medium companies. With over thirty years of experience serving privately held companies and S-corporations, Brian regularly reviews financial statements and handles tax planning and preparation.

Zafar Saleem

Zafar joined the J.A. Schilz team in October 2023. He holds a master's in economics from Punjab University, Pakistan, with an emphasis in Accounting and Finance, and is well versed in creating and reviewing financial statements. Caring by nature, he is always looking for ways to improve processes and quality of work. Outside the office, Zafar enjoys time with his family, volunteering, trying new restaurants, road trips, working out, and learning new things.

Ginny Jack

Ginny joined the team in September 2024. In her free time, she enjoys exercising, spending time with family, and relaxing outdoors.

Rebecca Miller, CB, CPA, CF

CB · CPA · CF

Becky brings more than 20 years of experience working with small business owners. She earned a BS in Accounting from Empire State College and a certificate in Small Business Management and Entrepreneurship. Licensed in both Wisconsin and Illinois, she is advanced certified in QuickBooks Desktop and QuickBooks Online. Away from the office, Becky enjoys time with her family, her ever-expanding garden, and cheering on the Brewers.

Josh Karfonta

Josh joined the team in April 2022 after graduating from the University of Minnesota-Duluth with a major in Management and a minor in Finance. He is eager to learn and grow in accounting and finance. Outside the office, Josh is a big sports fan who cheers on all of Wisconsin's teams and enjoys boating, ATVing, and hunting.

Haley Jakus

Haley joined the team in January 2026. She graduated from the University of Wisconsin-La Crosse with a degree in Finance and is excited to grow her knowledge in the financial and tax world. Outside the office, Haley enjoys spending time outdoors, staying active, and trying new restaurants.