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konecny.devČesky
A dark indigo lattice sphere with iridescent stained-glass windows, floating in mist. One window has a red rim.

Everything here is in its right place.

Jakub Konečný

A calm, well-kept corner of the web. I'm an activist, developer and artist from the Czech Republic. I love Rust, JavaScript and solid software.

Experience

Where I've worked: backend, mentoring, web automation, and now Excalidraw+.

  1. to now

    Excalidraw Full Stack Engineer

    I work on Excalidraw+, the collaborative whiteboard built on top of the open-source Excalidraw editor, across the whole stack.

    Some of my work: moving our apps from Next.js to TanStack Start, reworking Excalidraw libraries, a new auth foundation on Better Auth, the API and its MCP server, real-time collaboration, and moving our tests to Vitest.

    I also built the Excalidraw CLI, which manages an Excalidraw+ workspace from the terminal.

    • TypeScript
    • React
    • TanStack Start
    • Node.js
    • PostgreSQL
    • Drizzle
    • Better Auth
    • MCP
    • Vitest

  2. to

    Apify Web Automation Engineer

    I improved products and tools with Node.js, TypeScript, Docker and the open-source Crawlee framework.

    I developed and maintained a product used by 80,000+ users, in a team of two developers.

    I formalized how we test the software’s output (Jest, Zod), so users get a consistent experience.

    I talked with clients and built what they needed, including AI (LLM) integrations.

    • Node.js
    • JavaScript
    • TypeScript
    • Docker
    • Crawlee
    • Puppeteer
    • Playwright
    • Cheerio

  3. to

    Green Fox Academy Software Mentor

    My love for learning combined with my love for technology.

    During the course, I helped students understand modern technologies such as TypeScript, Node.js, React, and Docker.

    I also showed them how these tools can be effectively used in practice.

    With the students, we progressed from absolute basics all the way to programming a final full stack project.

    My team’s final project was a copy of 𝕏 (then still Twitter).

    • Node.js
    • React
    • JavaScript
    • TypeScript
    • SQL
    • Docker

  4. to

    Neit Consulting Backend Developer

    My first job. Even back then, I was a passionate enthusiast for JavaScript and TypeScript

    Therefore, I decided to take on the challenge of rewriting an outdated Node.js application, which was originally written in ES3 JavaScript, into modern TypeScript.

    This experience led me into the world of containerization with Docker and helped me improve my skills in application development.

    • Node.js
    • JavaScript
    • TypeScript
    • React
    • SQL
    • Docker

Through the glass

Things I've built, most of them for myself.

Forge

A clean workshop for every branch.

My dev environment platform. Open a pull request and Forge builds it into its own Docker environment from the repo’s devcontainer or compose file, then posts preview links back to GitHub.

Every environment gets SSH access, a web IDE and its own subdomains through Caddy, with live logs, resource stats, and cleanup once it’s no longer needed.

It’s built for teams: organizations, roles, encrypted secrets and API tokens, typed end to end from the Elysia API to the React UI.

  • TypeScript
  • Bun
  • React
  • TanStack Router
  • Elysia
  • Effect
  • Better Auth
  • Drizzle
  • SQLite
  • Docker
  • Caddy

Closed source. Ask me about it.

Renteller

Stories, told one message at a time.

A writing studio for visual novels. Authors write scenes, in-game phone chats and player choices as plain text, and export the whole story to Ren’Py.

The AI is a co-writer: it expands chapters into scenes, drafts from beats and each character’s voice, and keeps a summary of everything. Jev, TypeSafe’s decision model, keeps it honest by marking summaries that have gone stale and scenes that drift from the outline.

Art comes from ComfyUI on locally hosted models. Renteller queues each job, a small worker on a GPU machine renders it, and the author picks from the candidates, all in the story’s own style.

  • TypeScript
  • Bun
  • React
  • TanStack Router
  • Elysia
  • Better Auth
  • Drizzle
  • SQLite
  • AI SDK
  • OpenRouter
  • Jev
  • ComfyUI
  • Ren'Py

Closed source. Ask me about it.

Bungr INC.

Service with a smile. Mostly.

A first-person horror game about surviving shifts at a cursed fast-food joint, while a radio screams orders at you.

I’m making it with a small team, in the browser: Three.js for rendering, Rapier for physics and Koota as the ECS.

  • TypeScript
  • Three.js
  • Rapier
  • Koota
  • Vite
  • Blender
Play it at bungr.net

Arcanya

The glass bends light. Arcanya only bends parentheses.

My own programming language, written in Rust. It takes a lot from Lisp: interpreted, simple, and nice to look at.

The parser is built on nom, one of the most interesting parsing libraries I’ve come across, and the whole language is covered by extensive tests.

  • Rust
  • nom.rs
github.com/jameender/arcanya

Come through

Correspondence is welcome at any hour. Write to me about work, a project, or anything worth it.

[email protected]

I'm based in the Czech Republic