Hi HN,

I built AllPub (https://allpub.co) to solve a personal problem: I write technical articles and waste 3+ hours manually copying them to Dev.to, Hashnode, Medium, Ghost.

Each platform has different: - Markdown flavors (syntax highlighting, embeds) - Image handling (CDN requirements, optimization) - SEO requirements (canonical URLs, meta tags) - Formatting quirks (tables, code blocks)

AllPub connects to your Notion workspace (notion, dev.to, hashnode)and handles all of this automatically.

*Tech stack:* - Next.js (frontend) - Supabase (backend) - clerk (auth) - Platform APIs: Dev.to, Hashnode, Notion - Vercel (hosting)

*Challenges I faced:*

1. Notion's API is powerful but complex - Block-based structure (not linear Markdown) - Nested content handling - Image URLs are ephemeral (expire after 1 hour)

2. Each platform's Markdown parser is different - Dev.to: Liquid tags, front matter - Hashnode: GraphQL API, custom syntax - Medium: HTML-based (not Markdown) - Ghost: JSON content format

3. Image hosting/CDN - Notion images expire - Had to proxy/re-upload to stable CDN - Optimization per platform (sizes, formats)

4. Rate limiting across 4+ APIs - Orchestrated parallel publishing - Retry logic for failures - Status tracking per platform

*Technical decisions:*

- Why Supabase? (Postgres + Realtime, great DX) - Why Next.js? (SSR for landing page, API routes for webhooks) - Why not build a Notion plugin? (API limitations, better UX as standalone)

*Current state:*

The product is live and functional. Launching on Product Hunt this week.