Pawel Kowalski

From vibe-coding experiments to production systems built with agentic engineering.

Fundamental, and here to stay

I try to stay neutral on agentic engineering. But on one point I'm not: the shift LLMs are bringing to software engineering is fundamental, and it isn't going away, whether we like it or not.

To judge it honestly, to trade real opinions and experiences, to know what to embrace and what to resist: there's no way around using it yourself. Without first-hand experience, we only pass on what we've heard.

So I went and got some. The projects below are how I earned a view I can stand behind, stay critical of, and actually discuss.

Experiments

First-hand starts small: curiosity, low stakes, real tools in real use.

  1. The Klanglabor interface, with controls for stacking sine waves into a sound.

    Klanglabor

    My daughter asked me what a sine curve is. Paper worked until we tried to add two sines together, so I built a small app instead. Klanglabor lets you build and hear sound by stacking waves and harmonics. The first experiment.

    • experiment
    • sound
    klanglabor.ch
  2. The Klangtreppe interface for exploring the endlessly rising Shepard tone.

    Klangtreppe

    I've long been fascinated by the Shepard tone: a sound that seems to rise forever without ever getting higher. This is my explainer for the illusion, with adjustable layers and speed and a few ways to see what your ears are hearing.

    • experiment
    • sound
    klangtreppe.ch
  3. The verfasst interface for browsing the Swiss Federal Constitution by topic.

    verfasst

    Reading up on the Swiss cash initiative, I realised I barely knew the constitution it rests on. So I built a way to explore it: the Federal Constitution from Article 1 to 197, grouped by everyday topics like fundamental rights, finances and security, with current initiatives shown in context.

    • experiment
    • civic
    verfasst.ch
  4. The pointillism web app turning a photo into a field of coloured dots.

    pointillism

    An experiment with the pointillist effect: it turns any photo into a field of dots, in the spirit of Seurat. Everything runs in the browser, so the image never leaves the page, with presets, shapes and motion to play with, and export to PNG or HTML.

    • experiment
    • image
    pointillism.ch

Agentic engineering

The same hands-on approach, now under real production constraints, where opinions get tested.

  1. The HafCoin dashboard for booking coworking rooms and parking.

    HafCoin

    A production booking system for the nineteen companies sharing Haus am Fluss, a coworking house in Bern. Tenants get monthly coins to reserve rooms and parking; bookings sync to calendars and can be made through an AI agent. It was my first project built spec-first with AI coding agents (414 commits over 46 days), and the point where vibe-coding became agentic engineering for me.

    • production
    • agentic engineering
    coin.haus-am-fluss.be
  2. The Agentic Engineering & Harness Engineering deck, a spec-driven method with HafCoin as the case study.

    Spec-driven agentic engineering

    Building HafCoin taught me a way of working, so I wrote it up. It lays out the spec-driven, test-harnessed approach behind the build: break the work into small specified tasks, let an agent implement one at a time behind a full test suite, and review every step, the engineer shifting from author to reviewer, architect and spec-writer.

    • method
    • spec-driven
    coin.haus-am-fluss.be/training
  3. The Product Management Festival website homepage.

    Product Management Festival

    A production website for the Product Management Festival, a long-running, community-shaped conference for product people in Zürich. Built to stay fast, accessible and easy to maintain.

    • production
    productmanagementfestival.com
  4. The Vibehuus unconference website.

    Vibehuus

    A small, local unconference in Bern about vibe-coding and agentic engineering: no talks, just practitioners comparing notes on building software with AI agents. Co-founded with Jeremy Isnard.

    • community
    vibehuus.be

Real first-hand experience to hold an opinion, and to keep questioning it.