Cassidy Williams

Software Engineer in Chicago

Cassidy's face

Building W-9 Crafter

Helllloooo! I just shipped an app called W-9 Crafter that generates Form W-9s for you in a single click.

I first “pitched” this app in Discord way back in 2021 when I was complaining about how I have to make W-9s for all of my various contracting clients and newsletter sponsors, and the form information is always the same except for the date.

I stewed on that for a while, and then learned that the Form W-9s in the U.S. were being updated March 2024, and figured it was prime time to actually build a generator for Form W-9s!

The initial prototype

I first started building the app in the browser, using PDF.js and Download.js to take a PDF and edit it, and then download it to your computer.

W-9 Crafter initial web app

At first, I built something that would have you actually fill out an HTML form, populating the entire document, but realized all I really needed to generate every time was a new date on an existing form. Scope creep be darned!

Electron time

After that, I wanted it to generate the same form every single time I opened the app and clicked a button, just with a different date, so I decided to pull out Electron to be able to get the document path that I wanted to edit.

Normally, when you upload a file via the HTML <input> tag, you can’t get the file path, for very obvious security reasons. But, in Electron, it exposes file.path variable, so I was able to save that to local storage! So whenever you opened the app, it would edit the same form at the same location every single time. Woo hoo!

W-9 Crafter app

I thought I could be done there, but alas, Electron is huge. When I bundled the entire application, it was 300MB. That’s almost the entire storage a 1st generation iPod Shuffle could hold! Waaaay too big for a small app like this.

Incoming: Tauri!

Tauri seemed like the “thing” I should switch to because everybody loves Rust (heh), and because it ships significantly smaller apps.

I want to take a pause to do a quick shout out to Jacob Bolda and Alex Riviere (and other great Twitch viewers) for helping me convert the app on the stream! You saved my bacon!

Tauri was a really interesting thing to try out for this app in particular. They had just released version 2 of the framework, which made my application much easier to build, but with the con of the documentation not being fully up-to-date yet. There were some hiccups I ran into (for example permissions around opening files and writing new files) but nothing too bad.

The one thing that was particularly weird is that the default for Tauri saving files is that it overwrites an existing file instead of generating a new one when they have the same name (for example it doesn’t do blah.png and then blah (1).png), which was challenging to figure out. I ended up making a little file checker to solve that.

W-9 Crafter app

I will say… I found the Electron developer experience to be significantly smoother (all of my actual Electron code was less than 10 lines of code) than Tauri. Tauri though has more configuration, permissions, and is more “close to the metal” than Electron. I did like feeling a bit more in control of the outcome of the application and all that it did.

In the end, the app ended up being a teeny tiny 12MB instead of 300!! Absolutely worth it.

Gimme the app, Cassidy!

Okay! Stop shouting!

You can get W-9 Crafter from, and use discount code BLAHG20 to get 20% off because I like you. Generally. Currently. We’re working on our relationship.

This is my first time ever selling an app that I’ve made. I admit I don’t know a lot about pricing, and I haven’t shipped something solo like this before, so I was pretty nervous to make this go live! I chatted with several people who were super helpful in telling me how I should price based on how much time it could save someone, and how much time it saves me on average, how long it took me to build, and also just what they would pay for it. I’ve felt some impostor syndrome asking for… literally anything beyond “free”, BUT, I’ve made sales, so it’s good to be uncomfortable! You should charge for your work! Ahh!

It’s been a cool learning experience making a Product Hunt listing, a small demo video, and allll the social posts (Twitter, LinkedIn, etc).

Thanks for following along!

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