#002 — React 19.2: <Activity /> + AI Language Teacher
Date: May 22, 2026
Format: Technical deep-dive + Guest · ~40 min
Guest: Oleksandr Blazheiko
YouTube: youtube.com/live/R5IXxa1e8K4
Participants
Oleh Levchenko — Senior Full Stack JavaScript Developer (React / Node.js / AWS)
The AA · Cardiff, UK
YouTube @zloyleva · itfriday.community
Oleksandr Blazheiko — Software Development Engineer · Fullstack, 7+ years of experience
Ukraine
LinkedIn · itvibe.party
Building itvibe.party — a platform combining chat, a real-time AI translator, and a personal AI teacher. Real conversations are automatically turned into lessons: vocabulary, grammar notes, homework. Stack: Vue 3, Node.js, TypeScript, WebSocket, Redis, LLM/STT/TTS.
Key Takeaways
Block 1 — React 19.2: <Activity />
- React Conf 2025 announced the new
<Activity />component for preserving state when hiding UI - Problem:
display:nonehides the element but destroys state; unmount also loses state <Activity mode="hidden">preserves state and the DOM tree — similar tocontent-visibility: hiddenbut at the React level- Effects lifecycle differs: transitioning to hidden runs
cleanup, returning runssetupagain - Pre-rendering: hidden content can be rendered ahead of time for faster reveal
- Gotchas: not suitable for security-sensitive hiding (DOM still exists), increases memory footprint
Block 2 — itvibe.party (Oleksandr Blazheiko)
- itvibe.party — a platform combining chat, a real-time AI translator, and a personal AI teacher "Maestro"
- Core flow: two people speak different languages → STT → LLM translation → TTS → automatic lesson with new vocabulary and grammar notes
- Stack: Vue 3, Node.js, TypeScript monorepo (pnpm), uWebSockets.js, Redis, Drizzle ORM
- AI integrations: OpenAI, xAI, Mistral — isolated in a backend service layer, keys never reach the client
- Backend architecture: controller → service → repository → transformer
Timecodes
To be added after VOD review.