Yalçıncan Ulus

> Full-stack engineer based in Türkiye.

selected work

// one-click guest logins available where applicable

01 Bitig Flow | Document Sharing & Analytics Platform

Full-stack document sharing app where teams share files through secure links and see how visitors read them. DocSend / Papermark alternative.

stack: TypeScript TanStack Start React Node.js TanStack DB PostgreSQL Drizzle ORM Redis S3 (Garage) Better Auth Docker
links: live demo source

Bitig Flow | Document Sharing & Analytics Platform screenshot 1

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show details (8)

Write markdown in the app or upload PDFs and images, then share one document or a group of documents through a link
Each link has its own access rules: public, password, email, or email verified with a one-time code
Link analytics show visits, unique viewers, time spent on each page, how much of each PDF visitors read, and downloads
Team workspaces with owner, admin, and member roles, plus email invitations
Security features: hashed share passwords, rate limiting, file type checks on upload, and protected file delivery
One-click demo accounts that give each reviewer a private workspace, deleted automatically after 24 hours
Admin panel with two-factor authentication to control signups, demo access, and usage limits
Containerized with Docker Compose and deployed on Hetzner

02 Automated Price Tracking Platform

Full-stack price tracking app built as a Turborepo monorepo. Tracks grocery prices across 20+ sites and 10+ countries with time-series analytics and a public comparison frontend.

stack: TypeScript Turborepo Bun React PostgreSQL TimescaleDB Drizzle ORM Redis BullMQ Better Auth TanStack Router Playwright Docker Typesense (Elasticsearch/Algolia alternative) Sentry
links: live demo source

Automated Price Tracking Platform screenshot 1

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show details (12)

Scrapes prices from 27+ grocery sites across 19 countries using Playwright (browser rendering) and Cheerio (fetch) strategies, selectable per site
TimescaleDB hypertables with time_bucket and time_bucket_gapfill queries for historical price trend charts
Daily EUR-based FX rates fetched via BullMQ workers; all prices normalized to EUR for cross-country comparison
Pack-size normalization via per-item factors and per-site price divisors for fair cross-market comparisons
Four apps in one monorepo: internal API + admin dashboard, and a public API + storefront for product price comparison
Recharts-powered line and bar charts on the public frontend for visualizing lowest price over time per country
Bull Board UI for monitoring and managing scheduled scraping and exchange rate jobs
Better Auth for admin authentication; public API is fully read-only with no auth required
Drizzle ORM for type-safe PostgreSQL queries; Redis for BullMQ job queues and API response caching
Full-text search with Typesense (Elasticsearch / Algolia alternative) on the admin dashboard
Sentry for error tracking and log monitoring
Containerized with Docker Compose

03 Social Media Platform

Full-stack social media app built as a Turborepo monorepo with a Bun backend and React frontend.

stack: TypeScript Turborepo Bun React PostgreSQL Drizzle ORM Redis S3 (minIO) Better Auth TanStack Router WebSockets Docker
links: live demo source

show details (10)

Posts with image uploads via self-hosted MinIO S3, processed server-side with Sharp
Global and following feeds with cursor-based infinite scroll using TanStack Virtual
Real-time notifications delivered over WebSockets
Authentication via Better Auth with email/password, username, and guest login support
User profiles with follow/block system, bookmarks, likes, and comments
Admin dashboard with runtime system settings (toggle signups, guest login)
End-to-end type-safe tRPC-like API client; generated from the backend app type (elysiajs/eden)
Drizzle ORM for type-safe SQL with PostgreSQL
Redis caching for profiles, block lists, settings and session storage
Fully containerized with Docker Compose. Multi-stage builds using Turborepo prune

04 Messaging App

Real-time messaging application with JWT auth, friend system, and live WebSocket chat.

stack: TypeScript Node.js Express React Vite MongoDB Socket.IO Docker Bun
links: live demo source

show details (7)

JWT authentication and protected route guards
Friend request system; find users by email, send/accept/reject requests
One-on-one conversations with cursor-based paginated message history
Real-time messaging via Socket.IO rooms
Originally Node.js, migrated to Bun runtime. Still a standard Express.js app
Integration tests with Bun test runner, Supertest, and mongodb-memory-server
Frontend built with TanStack Router, TanStack Query, React Hook Form + Zod, and shadcn/ui

05 Blog Platform

Blog platform with a REST API, public-facing blog, and an admin CMS. Three separate apps.

stack: TypeScript JavaScript Node.js Express React Vite MongoDB Docker
links: live demo source

show details (5)

CRUD operations for blog posts and comments across three apps (API + CMS + public blog)
JWT authentication and role-based access control (admin/user)
Server settings to toggle comment creation and user signups at runtime
Both frontends built with React, TanStack Router, TanStack Query, and Zod
CI/CD pipeline with Docker and GitHub Actions for deployment

other projects

// more things I've built and contributed to

Multiplayer Location Guessing Game TypeScript Bun PostgreSQL Redis BullMQ D3.js Docker 2000+ games played

Multiplayer location guessing game played inside Discord. Hosts share a Google Maps link and a screenshot; players race to guess the country in chat.

Reads coordinates from all common Google Maps URL formats and finds the answer with Nominatim (OpenStreetMap) reverse geocoding
Guesses in plain chat with English and Turkish country names, ISO codes, and common aliases
Province mode for guessing Türkiye's 81 provinces by name or plate code, with separate stats
Point system with round and host multipliers that grow while a round stays unsolved
Leaderboards, player profiles, daily to yearly medals, and 30+ achievements
Map of wrong guesses drawn at the end of each round with d3-geo and canvas
PostgreSQL with Drizzle ORM for stats, Redis for live game state, and BullMQ for scheduled jobs
Admin tools for collusion review and a test mode that does not affect real stats
Compiled to a single Bun binary and deployed with Docker Compose
Over 2000 games played and 35.000+ guesses made by players

source