I've been a part of the FIRE (Financial Independence Retire Early) community for nearly 20 years. Early on, one of the ways that I found that I could connect with the community was to create useful online tools. Just about 12 years ago exactly, I launched cFIREsim.com.

At that time on the internet, believe it or not, there weren't many tools out there that helped people figure out the math behind retirement. There was a fairly popular site, FIREcalc that had a strong community behind it. However, it became clear that the developer of that tool had stopped taking suggestions and... retired! The community was clamoring for new features, and I figured that it would be a great project to start up. From the beginning, I listened to the community.

A new beginning

I don't know many software engineers that haven't thought about their "one big dream app". But here's the thing that I've learned: often, the best applications and tools are led by someone deep in that particular niche.

Dear reader, I'm that person for this community...

I'm releasing FIREproof in a "Beta" state, knowing that there is plenty of functionality already but also that there is a long runway for new features and improvements. If I was responding candidly to the question "How much is FIREproof like cFIREsim?", I'd tell you that FIREproof has 100% of cFIREsim's features with currently an extra 20% in new features, and a whole lot of room for more. Also, there are a handful of features implemented in the backend code (but not available to users yet, because there is no UI for them). For instance, cFIREsim does nothing to calculate or handle taxes. FIREproof is currently doing a basic calculation on both income and long-term capital gains taxes (with no mind of cost basis). So there's work to be done. However, there is a great foundation of code here, and I'm launching the site to receive community feedback and to look for a vision.

Current FIREproof quirks and half-measures:

Perhaps it is a bit much to get into the deficiencies of something that has just launched, but I want to provide full transparency so that people know how the tool works. And these aren't deficiencies, but rather partially completed features.

"Don't let perfect be the enemy of good." — Voltaire

• As previously mentioned: I'm not yet tracking cost-basis for transactions. This also means that I'm not keeping track of purchase dates and whether something is short-term or long-term. However, the code is already there for transaction-by-transaction tracking. For now, conservatively, long-term capital gains are taxed entirely, not just the gains.
• Required Minimum Distributions are not taken out from retirement accounts. Again, the code for calculating these RMD amounts is already there, it just hasn't been wired into the withdrawal process.
• Asset allocation: Whatever percentages that your accounts start at, is maintained throughout the simulation. I have rebalancing code that works well, but I realized that allowing users to enter the Asset Allocation for each account AND inputting an overall Asset Allocation to aim for, can cause big conflicts. I need to think about the user experience of this more.

This project is launching as a Beta version, but I'm including a subscription for a "Pro" version. This version will be the first to see new features, and will have a limited set of features available only to them. These subscriptions will support development of this tool and allow me to consider spending even more time on this project (Early Retirement anyone? A girl can dream).

Technology Stack

To satisfy some of the tech nerds out there, I wanted to briefly share the technology stack of FIREproof.

• Django 4.2 running on Python 3.11
• A PostgreSQL Database
• SvelteJS 4 along with SvelteKit for routing
• TailwindCSS for styling
• Nginx
• for authentication
• Docker for containerization and deployment.
• for payments.

The heavy lifting of the simulation is done in Python and sent to the frontend with secure Django REST Framework API endpoints.

Thank you!

Thank you for taking the time to read about FIREproof's journey. I’m incredibly excited to build this tool alongside a passionate community that values transparency, functionality, and long-term thinking. Your feedback, ideas, and support will shape where we go next—so please don’t be shy. Let’s make something amazing together.

-Lauren