Hello, I'm Krystian!
Full stack software engineer
About me
I am a full-stack software engineer based in Zurich, Switzerland, with the majority of my professional experience focused on developing enterprise web applications for major companies.
I have a deep passion for experimenting with new technologies and applying them in practice, whether through additional freelance work or by working on my own projects, some of which you can explore in my showcase section
Showcase projects
Artikel Meister
Artikel Meister is an app I designed and built to help German learners master the German articles. I got the idea when I wanted to improve my own German skills. After years of learning, I still found it hard to remember the right articles, and I knew others struggled with this too. I wasn’t happy with the apps already out there, so I decided to make my own!
Used Technologies:
React, Next.js, Stripe, Tailwind, Clerk, MongoDB
Citation Generator
Citation Generator was a professional freelancing project where my task was to develop an application to assist students in creating citations and bibliographies for their theses.
Used Technologies:
React.js, Node.js, Material UI
PlatePad
I built PlatePad as a personal project to explore creating a serverless backend using AWS services and to organize my favorite recipes in one place.
Used Technologies:
React.js, Material UI, AWS (Lambda, DynamoDB, API Gateway, Cognito, Amplify)
Core Skills
Java
Spring
Hibernate
SQL
React.js
Next.js
Angular
JavaScript
TypeScript
HTML
CSS
Node.js
Experience
Senior Software Engineer - EPAM Systems - Zürich, Switzerland
- Designed and developed an API Management Portal, integrating over 500 APIs using React.js for the frontend and Hibernate and Spring for the backend.
- Enhanced database query performance through optimization of Hibernate fetching strategies. Refined one query from an average execution time of 4 seconds to approximately 100 milliseconds.
- Implemented traffic validation policies in Java for an API Management Gateway, handling over 3 billion monthly calls.
- Developed a job scheduling system to update the database with data from various sources at set intervals, managing around 40 daily jobs across multiple application instances.
Associate Software Developer - Sabre - Kraków, Poland
- Worked on a rail ticket system application, utilizing Spring for the backend, and React.js for the frontend. Effectively collaborated in an Agile team of around 15 developers.
- Integrated APIs from various European companies into a single interface, enabling train bookings across 9 different countries.
- Improved the quality and test coverage by increasing the number of unit, integration, and end-to-end tests in the codebase.
- Upgraded the frontend by moving from classic React class components to functional components, using hooks for better separation of concerns and reducing boilerplate code.
Associate Software Developer - OPITZ CONSULTING - Kraków, Poland
- Worked on a German car leasing web application using Java and JavaScript.
- Provided consulting and customer service to German clients in German.