Sergei Karasev
Open to work12 years in the job. Mostly financial products, the last five years in Web3 and DeFi.
I take a feature from a loose ask to production: the interface, the API behind it, and the metrics and monitoring.
Stack: TypeScript, React, Next.js, Node.js, PostgreSQL
Location: Yerevan, Armenia · Remote, GMT+4 · Overlap: full EU, UK 6+ hrs, US East 3+ hrs · Independent contractor or EOR
A pool of RPC endpoints for ethers.js. Rate limit per endpoint, routing by latency, circuit breaker, retries that respect Retry-After. I wrote it when our sync job started failing on provider limits, and it kept us on a free plan. Tested with Vitest, published on npm.
Meeting transcription and live dictation for macOS. A native macOS app, a backend, and an MCP server so an AI agent can read the recordings and transcripts.
Log your habits and see if you reach your goals. Expo web client, Hono and oRPC on the backend, Postgres, Playwright e2e tests, decisions written down as ADRs.
Older open source: navigation, keyboard navigation for Smart TV apps, and zerg, a small logging library.
On dev.to. The story behind ethers-rpc-pool.