I Built 3 Free Developer Tools with Go and Astro — Here's the Architecture

I'm a developer who got tired of bloated online tools that require signup just to merge two PDFs. So I built three free alternatives and deployed them on a single ARM64 VPS. The Tools 1. ImgCrush — Image Optimizer imgcrush.dev Compress, resize, and convert images (JPEG, PNG, WebP). Drop files in, get optimized files out. No signup, no file count limits. 2. PDFCrush — PDF Toolkit pdfcrush.dev Merge, compress, split PDFs and edit metadata. Server-side processing means it works with large files that crash browser-based tools. 3. EU VAT Dev — VAT Calculator euvat.dev Calculate EU VAT across all 27 member states, validate VAT numbers against the official VIES database. Built for developers and businesses selling digital products in the EU. Architecture All three follow the same pattern: [Astro Frontend] → [Go API] → [SQLite] ↓ [File Processing] (libvips / pdfcpu) Why Go? File processing is CPU-bound work. Go's standard library handles HTTP, file I/O, and concurrency out of the box. The comp