Work with me

I build web apps, fix the ones that have become slow or fragile, and help teams get real results from AI.

I'm a freelance software engineer with over 20 years of experience building, scaling, and operating production web apps, APIs, and infrastructure, the last 15 of them mostly in Ruby on Rails and Postgres.

AI has changed how software gets made, for good, and I've embraced it fully. My job now looks less like writing every line and more like leading a team. I run several AI agents in parallel, set the direction, and make the calls that need judgment: architecture, trade-offs, and what's ready to ship. For you, that means weeks of work done in days.

AI also makes me stack-agnostic. Rails always feels like home, but I've shipped products in Rust, Go, Swift, and TypeScript. I'll work with the stack you already have, or pick the right one for the job.

Tell me about your project Book a 30-minute call

Piotr Chmolowski
Availability
Available for new projects
Based in
EU (CET) · overlaps US East mornings
Stack
Rails & Postgres first; also Rust, Go, Swift, TypeScript
Experience
20+ years in software, 15+ with Rails

What clients say

I've known Piotr for a decade and I'm always impressed with his skill and knowledge. When it came to updating the aging JSFiddle infrastructure, I knew who to ask and I was not disappointed. Piotr helped with the codebase and infrastructure stack modernization. After all was done I had two things: a modern stack, and saved 2-3x on infra costs.

Piotr has always been a thoughtful and intellectually rigorous partner — analytical, candid, and highly effective. His approach has helped us avoid many dead ends, while ensuring that what we built together stood the test of time on solid foundations. Despite several organizational pivots, business model changes driven by macroeconomic factors, and countless experiments, we maintained a high degree of flexibility, a modern codebase, and a highly motivated team throughout our years of collaboration.

How I can help

Build something new

You have an idea (or a spec) and need someone who can actually ship it.

  • New web apps and MVPs, from first commit to production
  • New features for your existing product
  • Internal tools, admin panels, APIs, and integrations

Fix and improve

Your app feels slower and more fragile every month, and you don't know what to fix first.

  • Performance, database, and downtime problems
  • Rails upgrades and legacy app modernization
  • Simplifying overengineered stacks and trimming dependencies
  • Infrastructure, deployment, and hosting costs
  • Code and architecture audits

AI for your team

Your developers use AI tools, but you're not sure they're getting much out of them.

  • AI coding agents and workflows set up for your team
  • Docs, tests, and CI that keep AI-written code in check
  • Internal AI assistants connected to your data, safely
  • AI features in your product that hold up in production

Ongoing help

You need a senior engineer or technical lead, but not a full-time hire.

  • Part-time senior developer embedded in your team
  • Maintenance, incident response, and code review
  • Fractional CTO: architecture, roadmap, hiring

Selected work

  • Years of work in days Built RAWmakase, a Rust photo editor, with AI agents that verify their own work.
  • 2–3x lower infrastructure bill Modernized JSFiddle's aging codebase and hosting.
  • Self-serve answers for the whole company An AI assistant that answers from code, database, and Stripe. Read-only, with no access to personal data.
  • Random downtime, gone Traced slow Postgres queries to noisy neighbors on shared CPUs; added monitoring and alerts.
  • 3 Kubernetes nodes → 1 server Moved an over-provisioned cluster to Kamal and kept the automated deploys.
  • Rails → Next.js without a rewrite Split the frontend gradually, so a new team shipped from day one.

Pricing

Start here

Health Check

€950 fixed price

A review of your codebase, infrastructure, and AI setup. Written report with top risks, quick wins, and a prioritized plan within one week.

Projects

from €3,500 per week

For building, fixing, and AI work. Billed weekly. Short jobs starting at €800 per day.

Retainer

from €2,500 per month

A set number of days each month for maintenance, incidents, reviews, or fractional CTO work.

Every engagement starts with a written proposal: scope, timeline, and price agreed before any work begins. Payment is upfront, weekly for projects and monthly for retainers.

A good fit if

  • You're a founder or a small-to-midsize team with a web product (or an idea for one)
  • You value simple, proven tech over the latest trend
  • You want someone who'll tell you when something isn't worth building
  • You want to use AI seriously

Probably not a fit if

  • You need a full agency with designers and project managers
  • Every decision needs sign-off from three layers of management
  • You need someone full-time, on-site

How it works

  1. Send me a few sentences about what you need, or book a call. No brief or spec required.
  2. I'll reply with questions or a proposal covering scope, timeline, and price. If it's not a good fit, I'll tell you and try to point you to someone who is.
  3. We start small with a health check or a first milestone, so you can see how I work before committing to more.

Side projects

Personal products I design, build, and run myself:

  • PixelPeeper Explore the camera settings and Lightroom edits behind photos. Ruby on Rails.
  • RAWmakase A fast, cross-platform RAW photo editor. Rust, GPU shaders.
  • ActionBar GitHub Actions in the macOS menu bar. Native Swift app.

Have a project in mind?

Big or small, new or existing: send me a short message about what you're building and where you need help. You don't need to have everything figured out.

Tell me about your project

Prefer to talk? Book a 30-minute call.