Who writes the code
I am Mariusz Szatkowski, a software developer based in Gdynia on the Polish Baltic coast, one hour ahead of London and Dublin. I have worked with WordPress since 2006 and have traded as WPPoland since 2007. From there the work grew into WooCommerce, TypeScript and Node.js, headless front ends in Astro and Next.js, and edge code on Cloudflare Workers.
I work alone. There is no mobile team, no design department and no bench of juniors I hand work to. The code you receive is code I wrote, and I answer for any of your existing code that I touch.
What I build
- Integrations. A WooCommerce store that has to agree with an ERP, a wholesaler’s price feed, Xero or Sage, or a warehouse. The API call is rarely the hard part. The hard part is deciding which system owns stock, prices and order status, and what happens when two of them disagree.
- Store engineering. Checkout logic, payments through Stripe, PayPal or Klarna, shipping through Royal Mail, Evri, DPD or An Post, and performance measured on real visitors rather than a lab score.
- WordPress plugins with a real data model: background jobs, REST and WP-CLI interfaces, and admin screens your editors can use without a manual.
- Headless front ends in Astro or Next.js on top of WordPress, deployed to Cloudflare. Worth it when the content model is stable; not worth it for a brochure site that changes twice a year.
- AI and MCP integrations that are read-only by default, logged and reversible.
The stack, and when I leave parts of it out
| Layer | Tool | I use it when | I skip it when |
|---|---|---|---|
| Server | PHP 8 on WordPress | You need editors, user accounts, plugins and cheap hosting | The workload is a long-running service with no content model |
| Commerce | WooCommerce | Catalogue and order data must stay in your own database | A hosted platform’s limits do not bother you |
| Services | TypeScript on Node.js | Integration workers, CLI tools, MCP servers | One WP-CLI command already does the job |
| Bulk data | Kotlin and Spring Boot | Long imports with a queue and retries | Your team only maintains PHP |
| Front end | Astro | Content-heavy, mostly static pages | The interface is a stateful application |
| Front end | Next.js | Application-like front ends | The site is mostly documents |
| Edge | Cloudflare Workers and Pages | Caching, redirects and small APIs close to the visitor | The job holds a database connection open for minutes |
| Tooling | Python | Data checks, document analysis, one-off migrations | Your team will maintain the code in PHP |
The language matters less than the boundaries. Good software is software where you can say which system owns which data, what runs where, and how to undo last Tuesday’s release.
Public code you can check without asking me
- wppoland/woocommerce-mcp: a Model Context Protocol server for WordPress and WooCommerce in TypeScript, MIT licence. Five tools (product list, single product, orders, sales report, post search) and none that can change the store. That decision is the part worth reading.
- wppoland/hidden-text-detector: a Python tool that finds white-on-white text, unreadably small fonts, text placed off the page and invisible Unicode characters in PDF and DOCX files. I wrote it because contracts and tenders started arriving with instructions aimed at an AI reader.
- The motylanogha profile on wordpress.org: 30 free plugins in the official directory (checked on 29 October 2026), including Shoplex, Quotlet, Plogins Customs and Polski for Polish stores. They are my own plogins.com products, built on PHP 8.1 with PHPStan and PHPCS.
- This website. wppoland.com is an Astro 7 build on Cloudflare Pages in six languages that runs automated checks on links, schema, sitemaps and headings before every release. In September 2026 I moved HTML minification onto worker threads; that step went from 910 to 199 seconds with byte-identical output.
Work experience
The roles are public on LinkedIn; I do not name the clients inside those contracts.
| Period | Role | What I worked on |
|---|---|---|
| Since Oct 2025 | Full-stack engineer (contract), Vienna software engineering agency | A subscription media and commerce platform: Composer monorepo, CI with two release gates, Stripe subscriptions and a Kotlin and Spring Boot service consolidating ERP, CleverReach and address data into Mautic. My part: importing subscription invoice lines and pushing them to Mautic in chunks, a supervised backfill, retries on transient Mautic errors, runbooks |
| Since Jan 2021 | WordPress, WooCommerce and PHP developer (contract), Equiqo, Berlin | WordPress, WooCommerce, HubSpot and Shopify on the Roots stack (Bedrock, Sage), performance and structured data |
| 2020 | WordPress developer, Itineris, Ipswich (UK) | Custom WordPress on Sage and Bedrock, CircleCI, performance and SEO |
| 2019 to 2020 | WordPress developer (freelance), what., Zurich | Custom WordPress, performance, structured data |
| 2016 to 2019 | WordPress developer, AirHelp | Multilingual, AMP and performance work on a high-traffic consumer site |
| Until 2015 | Web developer and internet marketing specialist, Vector Group, Gdynia | Websites, B2B commerce sites, search marketing |
Outside client work I organise WordCamp Gdynia, have been on the WordCamp Europe organising team since 2024, and co-organise CMSConf in Gdynia. Anonymised case studies, each saying what could and could not be measured: WooCommerce performance recovery, TYPO3 to WordPress, MCP server for an editorial workflow, headless WooCommerce on Cloudflare, headless migration plan, AI content operations. Stack detail: WordPress developer, WooCommerce developer, PHP developer, Astro developer, Next.js, Cloudflare edge, MCP servers.
Questions to ask any developer
- Where does the code live? In your repository, under your organisation, from day one. A developer who keeps the code until the invoice is paid is holding it hostage.
- How is a change tested before production? Look for staging, automated checks and a named person who approves releases. “I test on the live site” is a warning.
- How is a release undone? Anyone can deploy. Fewer people have rehearsed going back.
- What was measured before work started? Speed and conversion claims mean nothing without a baseline taken the same way.
- What will you not do? A developer with no stated limits will find them on your budget.
- Can I read something you wrote? Code, an article or a design document shows quickly whether the author names trade-offs.
Freelancer, agency or software house?
A single developer fits an integration or a rescue where one person on your side owns the decision: one head holds the whole problem. A new product that needs design, front end and back end at once, or six developers within a month, belongs with an agency or a software house. So does a mobile app.
The real risk with one person is continuity: illness, holidays, the day someone stops replying. With me that is covered by code in your repository from the first commit, documentation next to it, credentials held by you, and a written handover another developer can follow. Agencies looking for a standing technical partner can read the cooperation models on the partnerships page.
Taking over code from another developer
Most work starts inside a system that already runs, so the first days go on reading. I write down which plugins and services hold business logic, which cron jobs and webhooks run, and which data lives outside the database, for example in the payment provider’s dashboard. That map goes into the repository. I reproduce problems on a staging copy with customer records anonymised, so a fix is proven before it ships. Ugly but correct code stays; wrong code is replaced in small, reviewable steps.
Data protection and contracting from the UK and Ireland
Before I get access to any system holding personal data, I sign a data processing agreement under Article 28 of the GDPR, or of the UK GDPR for a UK controller. I use no sub-processors. The UK framework sits alongside the Data Protection Act 2018; in Ireland it is the GDPR with the Irish Data Protection Act 2018.
- You create a named account for me in your systems and remove it when the work ends. No shared admin passwords by email.
- I copy production data only when needed, keep it encrypted, anonymise it for staging and delete it afterwards.
- Every release maps to a commit, and every commit to a written reason.
The contract is a B2B agreement under Polish law. I invoice from Poland with EU VAT number PL7393037445, and your invoice carries your own VAT number. Payment dates are written into the scope, and work starts once the deposit, 30 to 50% depending on the project, has arrived.
How a project runs
- Brief in writing: the system, the problem, the deadline, repositories, hosting, and who decides on your side.
- Scope with assumptions: what is in, what is out, and what has to be true for the estimate to hold. Design, wireframes and content come from you and are listed as such.
- Baseline: access, a staging copy and measurements before the first change.
- Work in the repository: reviewable commits, each change on staging with a note, decisions recorded in the repository rather than a chat thread.
- Release and handover: a rehearsed rollback and documentation the next person can work from.
What I do not do
- Graphic design, wireframes or UX design. You supply the layout, often as a simple spreadsheet mapping elements to each view, and I build it into a working, responsive interface.
- Native iOS and Android apps. That is a different discipline.
- 24/7 on-call or guaranteed response times. I work alone and do not promise to pick up at three in the morning.
- Pretending to be a team. One person has one calendar. Large parallel workloads belong with an agency.
If you have a web or e-commerce system that has to run reliably and make sense to the next person who opens it, describe it in writing. More background is on the about page.
