What I Build
Production-Ready Tools
Tools Used by Developers Worldwide
EPUB to PDF Converter - Free, Private, In-Browser
Convert DRM-free EPUB ebooks to clean, formatted A4 PDF documents directly in your browser. Preserves typography, chapter images, and book spine order locally.
Free Online PDF Merger - Combine PDF Files In-Browser
Combine and reorder multiple PDF documents into a single contiguous file directly in your browser. Lossless vector quality, in-memory execution, and zero cloud uploads.
Free Online PDF to SVG Converter - Vector Extraction
Convert PDF pages into high-quality, scalable vector SVG files directly in your browser. Extract clean XML markup, vector paths, and downloadable ZIP archives.
Latest Engineering Articles
Discover how to use `pyproject.toml` to create, manage, and distribute Python packages for modern Python development. This comprehensive guide covers everything from build systems to dependency management and best practices for modern Python development.
Learn how to use the `__main__.py` file to make your Python packages executable. This guide covers the purpose of `__main__.py`, how it differs from `__init__.py`, and best practices for creating command-line interfaces.
A comprehensive guide to `__init__.py` in Python packages. Learn its core purpose, the hoisting pattern, package security with __all__, namespace packages, and 2026 best practices.
About Serhii Hrekov
I'm a Senior Software Engineer & System Architect specializing in Python, high-performance web backends, and cloud infrastructure (AWS, GCP). Currently working at nCube and Modigie, I created this platform to document real-world engineering solutions, production APIs, and developer tools.
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