
Aleksander Kolasinski
Software Engineer. Always learning.
I build software across the full stack. I've shipped production APIs, data pipelines, and client-facing sites for early-stage startups. I also freelance on the side.
Open to full-time software engineering roles.
Work Experience
June 2026 – Present
- Built marketing site from Figma mockups using Next.js, React, and Tailwind CSS.
- Implemented contact form with server-side email delivery and client/server-side validation.
- Improved Lighthouse score from 65 to 92; configured SEO metadata, Open Graph tags, and production security headers on Vercel.
Next.jsReactTailwind CSSResendZodVercel
Feb 2026 – Apr 2026
- Built production REST API endpoints with FastAPI and Python, integrating MongoDB to automate customer onboarding workflows on AWS EC2.
- Implemented JWT/JWKS authentication securing backend CRM services across a microservice architecture.
- Designed a time-series pipeline connecting MongoDB and TimescaleDB to serve property analytics to a React frontend.
FastAPIPythonMongoDBTimescaleDBReactAWS EC2JWT
Nov 2023 – Jun 2024
- Delivered a client-facing website for a medical practice with a responsive UI using HTML, CSS, and JavaScript.
- Built a contact form that automatically emailed patient inquiries to the doctor.
HTMLCSSJavaScript
Projects
Habit Tracking Web AppGitHub
- Built a full-stack web app using Node.js, Express.js, and PostgreSQL to manage daily habit tracking with persistent data storage.
- Designed a RESTful API with CRUD operations and a relational database schema.
- Created a responsive React/TypeScript frontend with modular architecture and asynchronous data fetching.
Node.jsExpress.jsPostgreSQLTypeScriptReact
BiteBook Food Journal
- Led a team of five to build a cross-platform food journal in Flutter with photo uploads, notes, and daily tracking.
- Implemented Firebase Authentication and Storage for secure image handling and real-time sync.
- Added sharing via dynamic links and QR codes, allowing users to duplicate entries into their own journals.
FlutterFirebase
Smoking Image Classification
- Built a deep learning pipeline using custom CNNs and MobileNetV2 transfer learning to detect smoking behavior.
- Improved performance through data augmentation, regularization, and ensemble modeling using TensorFlow and scikit-learn.
- Achieved 88% test accuracy with high recall using precision-recall metrics and ROC analysis.
PythonTensorFlowMobileNetV2scikit-learnNumPypandas
Education
Aug 2026 – May 2027
Aug 2022 – May 2025
Skills
Languages
Frontend
Backend
Databases
Tools