Vladislav Rajtmajer

Embedded C/C++ & PHP Backend Engineer

Plzeň, Czech Republic · remote · contract (IČO)

available now for new contracts

vladislav@rajtik:~$ cat about.md

I work at the seam between hardware and the backend.

An earlier decade was embedded and IoT: firmware in C on Atmel AVR and PIC microcontrollers, including a banknote validator, plus binary protocols between hardware and servers, telemetry pipelines and LoRaWAN.

For the last 12+ years I have built the systems on the other side of that wire: PHP and Laravel backends, REST and user-facing API design, PostgreSQL, and the boring reliability work that keeps APIs predictable.

The combination is the point. Ingesting data from field hardware across many device and payload versions is not a normal CRUD problem: the upstream is messy, the contracts have to be strict, and edge cases are the normal case rather than an afterthought. Having written the firmware end makes the backend end better.

# Open to long-term remote contracts: embedded C/C++, telemetry backends, or PHP/Laravel.

vladislav@rajtik:~$ ls projects/

SignalGenerator

embedded C++ · AVR

DDS signal generator on an Arduino Uno: AD9850 driven over SPI, SSD1306 OLED over I2C, rotary encoder with a hand-written debounce class, frequency persisted in EEPROM. Hobby build.

CaptchaAPI

privacy CAPTCHA · EU

Proof-of-work CAPTCHA, GDPR-first. No tracking, no Google. Ships with its own Laravel package and WordPress plugin.

Billify

invoicing API · CZ

Issue invoices over a clean REST API. Built for developers who'd rather call an endpoint than click through accounting software.

Exile to Exile

open-source product · PoE2

Free Path of Exile 2 companion built with Laravel, React and Inertia: build planner, passive-tree tools, loot-filter generator and shareable builds.

POE2 Toolkit

game tooling · OSS

Framework-agnostic TypeScript toolkit for GGPK extraction, typed game-data extractors and a headless passive-tree geometry engine with a React renderer. Used by Exile to Exile.

laravel-blog.cz

writing · CZ

A Czech-language blog where I write about Laravel and day-to-day backend engineering.

vladislav@rajtik:~$ cat packages.json --published

captchaapi/laravel Composer · Packagist

captchaapi WordPress.org · reviewed plugin

poe2-toolkit · @poe2-toolkit/ggpk npm · GitHub

ships across 3 ecosystems: Composer · WordPress.org · npm

vladislav@rajtik:~$ cat exile2exile app/Services/GameDataReleases.php

public function activate(string $version): void
{
    if (! $this->has($version)) {
        throw new RuntimeException("release {$version} is not staged");
    }

    $tmp = $this->currentLink().'.'.bin2hex(random_bytes(4));

    if (! @symlink("releases/{$version}", $tmp)) {
        throw new RuntimeException("could not create the swap symlink at {$tmp}");
    }

    if (! @rename($tmp, $this->currentLink())) {
        @unlink($tmp);

        throw new RuntimeException('could not swap the current symlink');
    }
}

Excerpt from Exile to Exile. Validated game-data releases activate through an atomic symlink swap: every request sees either the prior complete release or the new one, never partial data.

vladislav@rajtik:~$ git log --oneline --career

2022 - now PHP Developer · Freelance (OSVČ) Web apps, REST + user-facing APIs, Livewire, Vue.js, PostgreSQL.

2021 - 2022 PHP Developer · UBK s.r.o. Laravel development across multiple client products.

2018 - 2021 Developer · Freelance CMS for an international company. SCRUM, English-only daily comms. PHP 8, Nette, MariaDB.

2016 - 2018 Developer · MySolutions s.r.o. Dating platforms across 12 countries. SCRUM, English-only standups. PHP, Nette, MySQL.

before 2016 Embedded, IoT & systems engineering A decade of firmware in C (Atmel AVR / PIC) incl. a banknote validator, binary hardware protocols, telemetry APIs, LoRaWAN; Linux/Windows servers; Delphi/FoxPro business apps.

vladislav@rajtik:~$ cat stack.txt

embedded CCC++firmwaremicrocontrollersAtmel AVR / PICIoT / LoRaWANtelemetryLinuxPHPLaravelREST API designPostgreSQLPest / PHPUnitVue.jsElasticSearch

English: working proficiency, years of English-only daily standups. Czech: native.

vladislav@rajtik:~$ contact --now

vladislav.rajtmajer1@gmail.com · github.com/rajtik76 · linkedin.com/in/vladislavrajtmajer · x.com/VRajtmajer · laravel-blog.cz

vladislav@rajtik:~$ cv --download

CV - embedded C/C++ & backend · CV - PHP / Laravel backend
# same career, two emphases. Both PDF, English.

vladislav@rajtik:~$