Hi, I'm Justas - a full-stack software engineer with strong backend foundation (Python, FastAPI, SQL, data processing, networks, REST APIs), and solid frontend skills in HTML/CSS, Javascript, Typescript, and React. I build clean, maintainable and well-tested full-stack web apps and deploy them through CI/CD pipelines.
Before software engineering, I worked in product management, which gave me strong product intuition and attention to user value - experience that helps me make technical tradeoff decisions. I can bring value to software teams through my technical depth, product experience, ownership mindset, and passion for designing elegant software. Backend is my strength but I am comfortable working across the stack.
Below you'll find examples of my work and how to get in touch.
A full-stack web application that helps you see where your money goes. Import bank statements from multiple banks — the app extracts, normalizes, deduplicates, auto-categorizes, and stores transactions in a database. View them in a searchable dashboard and adjust spending categories to track your budget. It demonstrates end-to-end skills: async data pipeline design, pluggable architecture, domain modeling with typed contracts, idempotent processing, automated testing, and CI/CD.
Tech Stack
- Backend: FastAPI (Python 3.13), PostgreSQL, SQLModel/SQLAlchemy, Pydantic, JWT Auth (Supabase), modular architecture.
- Frontend: React 19 + TypeScript, Vite, Tailwind CSS, shadcn/ui, React Query
- CI / CD
- Backend unit + integration tests (90%+ coverage with pytest)
- mypy + ruff (linter/formatter), GitHub Actions, pre-push hooks
- Deployed on Koyeb (backend) + Cloudflare Pages (frontend)
Links
- Codebase / Documentation
- Live App. Sign up or click Try demo to explore without an account.
- API Docs
Screenshots
A full-stack web application that allows users to enter their body weight or get it from external sources (Google Fit API) and presents analytical insights in a modern web UI. It demonstrates end-to-end skills: full-stack development, OAuth 2.0, 3rd-party API integration with data normalization, modular backend architecture, automated testing, and CI/CD.
Tech Stack
- Backend: FastAPI (Python 3.12), PostgreSQL, JWT Auth (Supabase), Google Auth, Google Web REST APIs, modular architecture.
- Frontend: React + TypeScript, Vite, custom CSS (BEM style), responsive UI
- CI / CD
- Backend unit + integration tests (~85% coverage with pytest)
- mypy + formatter + linter, Github Actions, Git/PR hygiene
- Deployed on Koyeb (backend) + Cloudflare Pages (frontend)
Links
- Codebase / Documentation
- Live App. Sign up or use these demo credentials* :
- Email:
wtdemo@justas.tech - Pwd:
demo1
- Email:
- API Docs
*The credentials above give access to demo mode where you can try the features using a mock data source instead of real Google Fit API data. The app is currently in the testing phase on Google’s platform, so only the testing group users can access their Google Fit data using this app. Contact me to add you to the testing group (please mention your gmail address)
Screenshots
