Notes from the build.

Developer notes, findings, and code snippets. Mostly things I learned the hard way.

SHIPSep 04 202614 min

Signing a PDF Without Destroying It

Every free PDF signer rebuilds your contract into a new file. I wrote a PDF parser and an incremental-update writer so the original bytes survive, and then spent a day on an off-by-one that a helpful library had been hiding from me.

pdfjavascriptbrowsercanvasreverse-engineering

SHIPAug 17 202629 min

Building a Peer-to-Peer File Transfer Tool with WebRTC, Cloudflare Durable Objects and No File Server

How I built browser-to-browser file transfer for floi.dev: a 200-line Cloudflare Durable Object that relays a WebRTC handshake and nothing else, a DataChannel that streams gigabytes without dying, and the seven problems nobody warns you about.

webrtcfile transfercloudflare workersdurable objectsjavascriptpeer to peerweb developmentfile system access apistatic site

THOUGHTJul 24 20265 min

How AI Chatbots Remember Your Conversation (Even Though They Actually Don't)

Ever wondered how ChatGPT remembers your previous messages? The truth is, it doesn't. Learn how stateless AI models work, what multi-turn conversations are, and why long chats become slower.

aillmchatgptopenainode.jsjavascriptai developmentgenerative aiprompt engineering

SNIPPETJul 23 20264 min

JavaScript Set Explained Like You're 10

Learn what JavaScript Set is with simple examples. Understand why it is useful, how it is different from arrays, and why it makes many tasks much easier.

javascriptweb-developmentbeginnerses6programming