Build in public
Notes from building JustRec, a native Mac screen recorder: ScreenCaptureKit, on-device subtitles, hosting costs, and what worked, what broke and why.
Nicolas Ricardi8 min read
How we built a native Mac screen recorder on ScreenCaptureKit: separate writers on one clock, a Core Image compositor, encoder limits and the pitfalls we hit.
Nicolas Ricardi7 min read
How we run Whisper on Mac with WhisperKit and Core ML: why on-device, which model we picked, the 3-minute first load, disk space and language detection.
Nicolas Ricardi7 min read
Cloudflare R2 pricing for video, worked out for our app: storage, operations, Workers and D1, why expiring links keep the bill tiny, and what we don't know yet.
Nicolas Ricardi6 min read
Why JustRec's expiring links were a product decision: privacy, flat costs and delivery over hosting. The trade-offs, the objections and how expiry works in code.