01.about
Hi, I'm Marcin. I've been building web applications professionally since 2021 — mostly in TypeScript, React and Node.js. I don't stop at the frontend, though: I'm at my best when I can take a feature through the whole stack, from a component, through the API and database, to a Kubernetes deployment and a Grafana chart.
I've worked in large organisations — ING, LPP, T-Mobile — as well as in a small IoT start-up where one person owns a sizeable part of the system. Both taught me the same thing: what matters is code someone else will understand six months later, and decisions backed by data rather than gut feeling.
My academic background is geography. I wrote my master's thesis on landforms on Mars, and that past comes back whenever something needs to go on a map or raw data needs to become a readable visualisation.
- TypeScript
- React
- Next.js
- Node.js
- GraphQL
- Python
- Go
- SQL / MongoDB
- Docker
- Kubernetes
- Helm
- Grafana
02.experience
2024.08 — now
Senior Full Stack Engineer @ Pivotal
I help shape the architecture of a CRM platform in the R&D centre and develop the internal component library. I also make sure the UI holds up across multiple languages.
- Next.js
- React
- Ant Design
- Jest
- Kubernetes
2023.12 — 2024.08
Senior Full Stack Engineer @ ING
I worked on security tooling: a platform automating DDoS resilience tests, and an app organising the Offensive Security team's workflow — including generating pentest reports.
- Angular
- Next.js
- Flask
- TypeORM
- Ansible
- Azure Pipelines
2022.03 — 2024.07‖ in parallel
Full Stack Developer @ CrownIoT
Alongside my full-time roles I developed a platform for remote reading of water, electricity and gas meters. IoT device data, time series, dashboards and load testing.
- Next.js
- Apollo
- Django
- InfluxDB
- Grafana
- k6
2022.05 — 2023.12
Full Stack Developer · Silky Coders @ LPP
E-commerce for Sinsay and Reserved. I built the Sinsay Club loyalty programme and a product reviews system, plus a tool measuring Core Web Vitals of our stores and competitors — later used to improve frontend performance.
- React
- Express
- Go
- GraphQL
- MongoDB
- BigQuery
- Kubernetes
2021.02 — 2022.04
Full Stack Developer @ T-Mobile
Where it started: the customer self-service app and a data platform with interactive population migration maps — the first time geography and code met in one project.
- React
- TypeScript
- Apollo
- Node.js
- Python
03.work
A few things I've worked on. No NDA-protected details.
./cwv-monitor
Core Web Vitals monitoring
How fast are our stores compared to competitors? Instead of guessing, I built a tool that measures it regularly — and it provided the case for concrete fixes.
- BigQuery
- CrUX
- Lighthouse
- React
./ddos-automation
DDoS test automation
DDoS resilience tests run automatically from a single platform and wrapped up with a report on how they went.
- Angular
- Flask
- Ansible
./meter-reading
Remote meter reading
From a device in the basement to a chart in the browser: collecting readings, time series and dashboards for utility providers.
- Next.js
- Django
- InfluxDB
- Grafana
./this-site
This website
Static, bilingual, cookie-free. Astro on Cloudflare Pages with custom analytics that needs no consent banner.
- Astro
- TypeScript
- Cloudflare
04.now
- at work
- a CRM platform and component library at Pivotal
- into
- architecture, DevOps and practical use of LLMs
- off hours
- cycling, maps, weather and clouds — the real ones
05.contact
If you're looking for someone to join your team or want to talk about a project — drop me a line. I usually reply within one business day.
send an email →