Johannes Przymusinski
jprzymusinski.bsky.social
Johannes Przymusinski
@jprzymusinski.bsky.social
24 y/o Software Engineer from Bavaria / Germany
Full-Time developer, building SaaS products in the side 🤓
https://jop-software.de - https://mailcatcher.dev - https://zugferd-check.de - https://hu-wecker.de
Pinned
My first SaaS just launched on tinylaun.ch 🎉

Make sure to check it out and never have issues with testing email 🤓

Also leave some feedback and a 👍 so I cane improve the product even further for all of you 🚀

tinylaun.ch/launch/422

#buildinpublic
TinyLaunch
Discover and launch tomorrow's most exciting products today.
tinylaun.ch
Working in the rework of docs.mailcatcher.dev to be integrated in the new mailcatcher.dev website 🤓

A lot of work, but the absolute best part is, that I notice a loooot of improvements while re-writing the docs. Will implement them soon and tell you about

#buildinpublic
Welcome to Mailcatcher's docs
Get started with Mailcatcher and never worry about testing emails again!
docs.mailcatcher.dev
February 1, 2026 at 7:39 PM
Nice work for a Sunday evening, bringing the @ahrefs.bsky.social health score back up for mailcatcher.dev

Missed a few little edges during the relaunch of the landing page, mainly due to trailing slashes and some content improvements 🦾🚀

#buildinpublic
January 25, 2026 at 8:52 PM
#sundays are for #OpenSource

Therefor I launch git-merge-to under MIT, a small git extension that allows you to merge your current branch into any other easily.

Install from homebrew or manually 🚀

Check it out at github.com/jop-software... and let me know what you think

#buildinpublic
GitHub - jop-software/git-merge-to: Simple git utility that allows you to merge your current branch into another
Simple git utility that allows you to merge your current branch into another - jop-software/git-merge-to
github.com
January 25, 2026 at 11:09 AM
As promised 🚀 here it is ... mailcatcher.dev now supports STARTTLS, allowing SMTP connections to be encrypted 🔐

See our changelog mailcatcher.dev/changelog/20... and docs docs.mailcatcher.dev/foundamental... for more information 🤓

#buildinpublic
January 24, 2026 at 1:14 PM
I just finished one of the most important new features for mailcatcher.dev today and tested it on production 🤓

Will prepare a proper changelog entry and tell you more about it soon 🚀

What do you think it could be? Let me know 👇

#buildinpublic
Mailcatcher - Email Testing for Developers
Capture and test emails from your development environment. View HTML previews, inspect headers, and collaborate with your team safely.
mailcatcher.dev
January 23, 2026 at 8:09 PM
Always when I have an idea for a small side project, I find someone that has already built it, but open source, for free and with even more/better features I had in mind 😂

Still worth building which this competition?

#buildinpublic
December 8, 2025 at 8:22 PM
What I Shipped - 2025-01-29

mailcacher.dev
- Finished inline embedded images
- Migrated from pnpm to bun

jop-software.de
- prepared for more details content pages

Also worked on a (for now) secret side project 🤓

#buildinpublic
mailcacher.dev
January 29, 2025 at 11:09 PM
What I Shipped - 2025-01-28

For mailcatcher.dev (@mailcatching)
- updated to @symfony 7.2
- auto generating slugs for tenant / projects (customer feedback)
- started implementing rendering of inline attachments

#buildinpublicc
Mailcatcher - Testing emails with ease!
Mailcatcher is the solution to all your email testing problems! Simple integration and Powerfull features
mailcatcher.dev
January 29, 2025 at 5:40 PM
Have you ever launched a product on one of the platform? Do you think it’s worth it?

I today finally launch my product on tinylaunch, check it out if you want 🤓

www.tinylaun.ch/launch/422

#buildinpublic #saas #development
Mailcatcher - tinylaunch
Mailcatcher makes email testing effortless and organized.
www.tinylaun.ch
January 18, 2025 at 10:28 PM
My first SaaS just launched on tinylaun.ch 🎉

Make sure to check it out and never have issues with testing email 🤓

Also leave some feedback and a 👍 so I cane improve the product even further for all of you 🚀

tinylaun.ch/launch/422

#buildinpublic
TinyLaunch
Discover and launch tomorrow's most exciting products today.
tinylaun.ch
January 18, 2025 at 8:06 AM
What do you use to host your #buildinpublic projects?

Some PaaS like Vercel, Cloud Computing on AWS or some VM / Server Provider like. Hetzner?
January 16, 2025 at 9:20 PM
Ok ... I probably should implement some sort of Captcha / Honeypot in my registration flow 😂

#buildinpublic
January 16, 2025 at 6:17 PM
Just finished the relaunch of my first launched SaaS product. Make sure to check it out 🚀

mailcatcher.dev
January 16, 2025 at 6:15 AM
Just started a new SaaS Project Idea 🚀

It includes the #YouTube Data API and implement a feature I really miss in YouTube.

Will tell you more concrete things when the MVP is ready 🤓

What features are you missing in YouTube?

#buildinpublic
November 29, 2024 at 5:11 AM