Projects

I've been writing code for years — automation scripts, web scrapers, data analysis, and everything in between.

A few of the things I've built on my own time — each card links to the source code or the live app:

Featured

Web app

Next.js
React
TypeScript
Postgres
Vercel
Railway

hideki.one

This site

The site you're on: a full-stack Next.js 16 / React 19 / TypeScript app on Vercel, talking directly to Postgres and S3-compatible buckets on Railway — JWT auth in httpOnly cookies, a blog with MDX stored in the database, file sharing by link (presigned uploads) and a one-shot inbox for receiving files, guarded by rate limiting, CSRF checks and a CSP.

Bilingual routes with proper hreflang, SQL migrations, over 1,500 tests with a 90% coverage floor enforced in CI, plus four small Bun services on Railway (streaming zip, mail relay, /sos health monitor, lease-cleanup cron). Private repository.

Private repository

CLI

Python
Selenium
uv

viewlyt (opens in a new tab)

A CLI that pulls text out of YouTube

A CLI and typed Python library that extracts a video's transcript, its comments (with likes, dates and replies) and its related-videos sidebar, writing clean, LLM-ready Markdown.

It drives headless Chrome through Selenium. Two optional modes ship with it: vl ask runs retrieval over what you already collected without re-scraping, and vl live analyzes a livestream chat in real time.

Source on GitHub

CLI

Python
DuckDB
OAuth

cmon (opens in a new tab)

A usage monitor for Claude subscription plans

A CLI that tracks Claude plan consumption over time: it reads the official usage endpoint, stores snapshots in DuckDB, and reports burn rate, projections and 5-hour-window alerts.

It resolves the token through a fallback chain — an environment variable, the OS secure vault (Keychain, Credential Manager, Secret Service), or Claude Code's own credential — and refreshes OAuth by itself when it expires, never writing anything in cleartext.

Source on GitHub

More projects

API
- TypeScript
- Next.js
- Vercel
B3 company data scraper API
REST endpoint that returns structured data for any company listed on B3 (Brazil's stock exchange) — pass the ticker via a ticker request header.
View details
Bot
- Python
- Selenium
- OpenAI
PDF filing summarizer bot (opens in a new tab)
Open-source bot that uses Selenium to download company filings from Status Invest, summarizes them with the OpenAI API, and emails the summary.
Source on GitHub
Notes
- Python
- Jupyter
flupy (opens in a new tab)
Fluent Python reading notes
Reading notes on Fluent Python, by Luciano Ramalho. I worked through Python Fluente, the Brazilian edition — so the notes themselves are written in Portuguese.
Source on GitHub
CLI
- Python
- OpenAI
vox (opens in a new tab)
Terminal chatbot
Terminal chatbot built on the OpenAI API.
Source on GitHub
Library
- Python
- Selenium
- FastAPI
scrapthere (opens in a new tab)
Web scraping API
Small Python library that makes web scraping straightforward and exposes the results through an API.
Source on GitHub
Web app
- React
- Next.js
- Vercel
Compound interest calculator (opens in a new tab)
Front-end app hosted on Vercel that calculates compound returns on recurring contributions. Built with React and Next.js.
Open app
Script
- Python
- smtplib
emailme (opens in a new tab)
Email notification service
Uses a Gmail app password and Python's smtplib to send email to any recipient.
Source on GitHub
Script
- Python
- OpenAI
Quiz generator (opens in a new tab)
Generates multiple-choice questions from any text file with the OpenAI API — you choose how many alternatives each question gets and whether the correct answer is marked.
Source on GitHub
Script
- Python
- NumPy
Investment portfolio return analysis (opens in a new tab)
Uses NumPy to model an investment portfolio as a polynomial in (1+i) and solves for the return rate.
Source on GitHub