Karol
Bartkiewicz
software
developer
Bartkiewicz
01
Skills
Frontend React · Astro · Webflow · JavaScript · TypeScript · Next.js ·
HTML · CSS · SCSS · Tailwind · Framer Motion
Backend Node.js · SQL · TypeORM · Strapi
Testing Cypress · Jest · React Testing Library
DevOps Git · GitHub Actions · GitLab CI
Automation AutoHotkey · PowerShell · Bash · VBA
02
Experience
Frontend Developer
Web extension for hotel price comparison (Vio.com), company website & blog, Webflow landing pages.
Vio.com — hotel price comparison extension
TypeScript · Vite · Vitest · HTML
· CSS
- Optimized bundle size by excluding unused modules and features during the build process
- Rewrote core parts of the project to speed up creation of new features, enabling accurate estimations of new system integrations
- Implemented scraping logic and plugin UI across Booking.com, Expedia, Hotels.com, Tripadvisor
- Introduced async element scraping API crucial for integrating with AJAX or SPA based websites
- Conducted code reviews
Business website, blog & technical blog
React · Next.js · TypeScript · Zod
· react-query · Strapi · PostgreSQL
· Kubernetes · Docker · SCSS ·
Tailwind
- Optimized blog page to use 10× less data per request, shortening build time and reducing bandwidth
- Introduced E2E tests for crucial multi-step forms using Cypress
- Introduced unit tests launched pre-commit and before pull request merge
- Migrated all projects from GitLab Jobs to GitHub Actions
- Created multi-step forms with validation logic using Zod and React Hook Form
- Used Kubernetes to search logs and debug active or failed deployments
- Improved developer experience using Docker for backend application setup
- Optimized SQL queries to reduce data usage
- Conducted code reviews
Webflow business website
Webflow · JavaScript
- Written custom JavaScript where no-code solutions were insufficient
- Debugged and tested contractor-developed landing pages
- Developed new pages using Webflow
Warranty Specialist & Business Automation Developer
Browser extension merging internal MB web apps, DMS workflow automation tools, analytics application.
Internal workflow browser extension
TypeScript · React · Zod
- Built a browser extension automating data exchange between multiple internal Mercedes-Benz web applications
- Implemented DOM scraping using async getters and MutationObserver
DMS workflow automation
AutoHotkey · PowerShell
- Replaced manual entry of part numbers (up to 60 items per order) with single-click automation
- Increased processing capacity from ~10 to 20+ orders in the same time window
- Automated Windows Forms interactions: field population, click simulation, cross-system data copying
- Implemented automated mistake logging — errors stored in SQLite and sent via SMTP to advisors and supervisors
- Reduced risk of manual typos in part numbers and VIN entries
- Used daily in operational workflow for over 3 years
Usage & error analytics application
Node.js · TypeScript · TypeORM · SQLite
· yargs
- Usage analytics
- Document error tracking and analytics
Transport cost estimation tool
Excel · VBA
- Designed Excel-based tool aligned with official Mercedes-Benz pricing policies
- Implemented tiered pricing logic based on vehicle type, distance and transport scenario
- Automated cost breakdown generation with ready-to-send explanation text
- Used several times per week in live service operations for over 3 years
Frontend Developer & Co-founder
Community website for web developers.
Website for Web Developers
Playwright · GitHub Actions · Astro ·
TypeScript · React · Tailwind