I made a simulator for personal finance (5 year update)

In 2021 I shared ProjectionLab on HN[0], and I've now spent half a decade making it better.

It started as a simple financial simulator side project. In 2023, I quit my job to work on it full-time. And today it's a pretty robust financial planning and optimization tool.

This month, I added a tax strategy engine to automatically coordinate Roth conversions, tax-aware withdrawal blending, and gain harvesting, around constraints like targeting a federal tax bracket, preserving ACA subsidies, respecting IRMAA cliffs, or avoiding NIIT.

A beam search wraps around this to help find the best strategy for your objectives (maximizing net legacy, minimizing lifetime taxes, etc.)

It's been pretty cool to see that in the median case this often saves about $300k in lifetime taxes.

If you tried PL years ago in one of my original Show HNs, I'd love to hear what feels different now, or what areas still need more attention.

I've incorporated a lot of this community's feedback, e.g. there is now a free tier with basic forecasting that does save your data. And I've added more international depth for folks in Canada, UK, AU, and some other locations.

Also noteworthy:

- Flexible spending based on portfolio performance to help simulate more realistic spending profiles and boost Chance of Success.

- Net legacy estimation, estate planning, and charitable giving (QCDs, DAFs, etc)

- Government benefit estimation (US: Social Security, Medicare, ACA subsidies, Canada: CPP, OAS, GIS, etc)

- Monte Carlo options like block bootstrap (stitch random blocks of consecutive years to mix eras while keeping year-to-year patterns)

- Changelog [1]

[0] previous Show HNs: 2021 (https://news.ycombinator.com/item?id=26969173), 2022 (https://news.ycombinator.com/item?id=31083093), 2023 (https://news.ycombinator.com/item?id=36849502)

[1] https://projectionlab.com/changelog