Olivier Piasecki · Poznań, Poland

Java Backend Developer

I build Java backend systems, multiplayer infrastructure, and web applications for real businesses. I designed, built, and continue to operate Boxhunt.pl, a platform that has handled more than 1,300 concurrent players.

Available for junior backend roles, internships, and freelance projects.

View projects View résumé Contact me GitHub

Selected work

Systems I have shipped and maintained

Production platforms, open-source maintenance, and client work, described by responsibility and outcome.

Open-source client mod · 2024-present

TwemojiChat

Open source

A client-side mod that adds emoji autocomplete and Twemoji rendering to Minecraft chat.

Click to expand more information Click to collapse information

Context

One feature set must remain compatible across three mod loaders and 19 supported Minecraft version lines, from 1.20.1 through current releases.

Responsibilities

  • Cross-loader architecture and compatibility maintenance
  • Generated data and asset tooling
  • CI, releases, bug fixes, and public documentation

Technical approach

  • Shared common logic with loader- and version-specific modules
  • Pipeline that generates font sheets and shortcode aliases from upstream emoji data
  • Automated builds and checks through GitHub Actions

Scale and outcome

  • Fabric, Forge, and NeoForge support
  • 600+ downloads on Modrinth
  • MIT licensed and publicly maintained

Freelance client website · 2024

wynajem-samochody.pl

Production

A responsive production website for a truck rental business with a fleet of around 120 vehicles.

Click to expand more information Click to collapse information

Context

The business needed a clear way to present its rental offer, fleet, sales listings, and contact paths.

Responsibilities

  • Requirements, responsive interface implementation, and production deployment

Technical approach

  • Rental offer presentation
  • Vehicle gallery and buy/sell section
  • Direct lead-generation and contact flow

Scale and outcome

  • Delivered to a real business
  • Deployed and publicly available

Freelance client website · 2025

algupominki.pl

Production

A production marketing website for a promotional-products company in Poznań.

Click to expand more information Click to collapse information

Context

The company needed a responsive B2B presence that explains its services, organizes product catalogs, and makes enquiries straightforward.

Responsibilities

  • Requirements, responsive interface implementation, and production deployment

Technical approach

  • Product catalog presentation
  • Branding and service information
  • B2B lead-generation flow

Scale and outcome

  • Delivered to a real business
  • Deployed and publicly available

Current project · In development

3D-printing commerce platform

In development

A custom store and commerce platform for a 3D-printing business, currently being built around Medusa.

Click to expand more information Click to collapse information

Context

The project is in active development; implementation and deployment outcomes are not presented as complete.

Responsibilities

  • Storefront and commerce-platform implementation

Technical approach

  • Medusa-based commerce foundation

Scale and outcome

  • Status: in development
  • Medusa
  • TypeScript

Experience

How the work is structured

  1. Freelance Web Developer

    Client business projects

    2024-present

    Delivered production websites for two businesses, covering requirements, responsive implementation, deployment, and clear lead-generation paths.

  2. Founder / Lead Developer

    Boxhunt.pl

    2022-present

    Design, develop, deploy, and operate the platform, its custom Java systems, and the infrastructure supporting releases and large traffic peaks.

  3. Open-source Maintainer

    TwemojiChat

    2024-present

    Maintain multi-loader and multi-version compatibility, generated assets, CI, releases, bug fixes, and public documentation.

Skills

Technologies in context

Primary

Used most often in my backend and platform work.

  • Java
  • Kotlin
  • Paper API
  • Velocity
  • Gradle
  • Git
  • Linux
  • Docker

Backend and data

State, communication, and operations in a multi-server environment.

  • Redis
  • MongoDB
  • MySQL
  • asynchronous processing
  • configuration systems
  • cross-server communication

Web

Production client sites and storefront development.

  • TypeScript
  • React
  • Vite
  • Node.js
  • Express
  • HTML
  • CSS

Engineering Practices

Taking work from implementation to an operated release.

  • GitHub Actions
  • CI and releases
  • testing
  • deployment
  • debugging and performance
  • documentation

About

Backend focus, production experience

About me

I am a 16-year-old developer from Poznań, primarily working with Java and backend systems. I have built and operated Boxhunt.pl, delivered production websites for two businesses, and maintain TwemojiChat across multiple Minecraft loaders and versions. I am looking to gain commercial software engineering experience while working alongside experienced engineers.

Contact

Let’s talk

Open to junior backend roles, internships, project-based cooperation, and freelance work.

Direct contact

contact@bruhdows.com github.com/Bruhdows ↗ LinkedIn ↗

By sending this form, you acknowledge the privacy policy.