Senior Backend Engineer: AI-Scale Infra, Remote

Advatix is seeking a Senior/Staff Backend Engineer to help build and scale large-scale infrastructure for conversational AI. You will own backend services in TypeScript/Node.js and Python, scale simulation infrastructure to 200K+ concurrent voice calls, and design a purpose-built database for AI workloads. The role is remote within the United States, offers $160,000–$240,000 per year with 0.2%–1.0% equity, and requires strong ownership and fast iteration in a startup-like environment.