Eleventh Edition

When Tandem was founded in 2011, we tried the “top of the line” financial planning programs
available and we weren’t impressed with the results. We thought we could make something better,
so in 2014 Angus, Colin, and Dr. Shaun Pfiefer, CFP®, created a financial planning model to help clients
make smarter decisions about when to retire, when to take social security, what kind of retirement
income their asset base can reasonably support, how much house they can afford, and more.
Last year, Angus decided it was time to transition the original financial planning model’s programming
from Visual Basic to Python to make it more robust and efficient. To that end, Tandem engaged
probabilistic programmer Austin Garrett out of the Massachusetts Institute of Technology (MIT) to work
on the project. Austin is an AI engineer focusing on Bayesian inference and probabilistic programming.

Austin Garrett

AI Engineer

C. Angus Schaal, CFP®

Senior Managing Director

Angus: Tell us about yourself, Austin.

Austin: I was born and raised in Gilbert, Arizona. I have both my undergraduate and graduate degrees from MIT. I’m a probabilistic programmer, systems engineer, and open-source developer. As an undergraduate, I studied computer science and physics, researching applications of neural networks to program induction and models of intuitive physics. My graduate school studies were in probabilistic computing. Prior to coming to Tandem, I was an AI Software Engineer supporting basic research with the MIT-IBM Watson AI Lab.

Angus: What does Tandem’s financial planning model do?

Austin: Using both mathematical modeling and computer simulation, Tandem’s proprietary financial planning model utilizes a combination of fixed data points like your age, current savings, and social security along with a few variable data points such as retirement spending and portfolio returns to help predict the likelihood of success in retirement given certain conditions and parameters. The program calculates the probability of your investment portfolio sustaining your standard of living
until death. Many of you have used this model during financial planning meetings with Tandem.

Angus: What will change about the financial planning model?

Austin: The updated model will be complete soon and will be known as Handlebar™. It will offer an additional level of customization which will better help us build each model around the individual client and their unique circumstances and needs. Tandem will be rolling this out to clients in the first part of 2024.


Tandem Wealth Advisors LLC (“Tandem”) is an SEC-registered investment adviser. The information published herein is provided for informational purposes only and does not constitute an offer of investment advisory services. All information is subject to change without notice. Nothing contained herein constitutes financial, legal, tax, or other advice. No investment process is free of risk, and investors may lose all their investments. Past performance is not indicative of current or future performance and is not a guarantee. The opinions expressed in this document may not fit your risk and return preferences. The information provided is obtained from sources believed to be reliable, but we cannot attest
to its accuracy. Past performance is not necessarily indicative of future returns. Certain information contained herein constitutes “forward-looking statements,” which can be identified by the use of forwardlooking terminology such as “may,” “will,” “should,” “expect,” “anticipate,” “project,” “estimate,” “intend,” “continue,” or “believe,” or the negatives thereof or other variations or comparable terminology. Due to various risks and uncertainties, actual events, results, or actual performance may differ materially from those reflected or contemplated in such forward-looking statements. Nothing contained herein may be relied upon as a guarantee, promise, assurance, or a representation of future events or conditions. Additional copies of Tandem’s ADV Part 2A and/or Privacy Policy are available upon request by phone at 602-297-8600 or by email at [email protected].

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