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MrJSA Technologies

From schematicto shipped app.

I design PCBs, write the firmware that runs on them and build the apps and software that talk to them — one engineer, the whole stack.

See my work Get in touch GitHub
Shop

Straight fromthe workbench.

Products designed and built by MrJSA Technologies — order them directly in the official shop.

  • Designed & built in-house
  • Secure checkout
  • Shipped from Germany
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What I do

Services

PCB Design

Schematics and multi-layer layouts that are ready for manufacturing — from first prototype to small series.

  • Schematic capture & component selection
  • 2–6 layer layouts, DFM checked
  • Fabrication & assembly files

Embedded & Firmware

Reliable firmware for microcontrollers — written in Rust or C, close to the metal and well tested.

  • ESP32, STM32, nRF and more
  • Sensors, motors, wireless & low power
  • Bring-up and debugging of new boards

App Development

Mobile apps for Android and iOS, published in the stores and connected to your hardware or backend.

  • Android & cross-platform apps
  • Bluetooth / Wi-Fi device companions
  • Store listing, release & updates

Software & Web

Desktop tools, web apps and backend services — fast, maintainable and deployed with Docker.

  • Rust & TypeScript services
  • Web frontends with Svelte
  • Docker, CI/CD & self-hosting

Live Sound & Audio

Digital mixing consoles, stage networks and soundcheck workflows — from patching an X32 to tuning the PA, plus the hardware and software around them.

  • Behringer X32 / Midas M32 setup, routing & scenes
  • AES50 stageboxes, Ultranet & in-ear monitoring
  • Remote control via OSC, X32-Edit & Mixing Station
Selected work

Projects

All projects
Software
Software Live

RustCraft Webshop

A self-hosted webshop with a Rust backend and SvelteKit storefront and admin — payments, invoices, inventory and German/EU legal features in one Docker stack with one-click updates.

  • Rust
  • Axum
  • SQLx
  • PostgreSQL
Read more
Software
Software Live

This Website

A fast, fully static portfolio built with Svelte and served by a tiny Rust web server in Docker.

  • Rust
  • Svelte
  • SvelteKit
  • Docker
Read more
Audio
Audio Live

X32 / M32 Field Guide

A complete technical manual and field guide for the Behringer X32 and Midas M32 digital mixing consoles — 15 chapters from gain staging to AES50 stageboxes, in English and German.

  • Live Sound
  • Behringer X32
  • Midas M32
  • AES50
Read more
Available now

Apps

All apps
Available Android

HarmonicFlow

Chord sheets, setlists and live performance for worship teams and bands — ChordPro songs, transposing with capo, chord numbers, a live view, metronome, ambient pad, tuner and setlists shared with the whole band.

Read more
Toolbox

Tech I work with

01Hardware

  • KiCad
  • Schematic & layout
  • DFM / JLCPCB
  • Soldering & rework

02Embedded

  • Rust (embassy, no_std)
  • C / C++
  • ESP32
  • STM32
  • nRF52

03Apps & Software

  • Rust
  • Svelte
  • Kotlin
  • TypeScript
  • Docker
  • Linux
About

Hi, I’m Joshua.

hover to glitch

I’m an engineer who enjoys the full journey of a product: from the first sketch of a circuit, through the board layout and firmware, all the way to the app in the store.

With MrJSA Technologies I build my own products and help others bring theirs to life — pragmatic, well documented and built to last.

Based in
Germany
Focus
PCBs, embedded, apps, live sound
Languages
German, English
Contact

Have a project in mind?

Whether it is a board, a device, an app or something in between — send me a message and I’ll get back to you.

joshua@mrjsa.com GitHub LinkedIn