Staff/Principal Software Engineer

What we're looking for: We need a Staff/Principal-level backend engineer with 8+ years of experience building and deploying cloud-based services at scale who thrives in a fast-moving startup environment. You should be comfortable working as a strong IC with technical autonomy, have a track record of shipping zero-to-one platform products, and bring adaptability across tools and programming languages.

Bonus points if you have experience with AI products, founder experience, or have worked at high-caliber companies like Databricks or similar AI/infrastructure startups.

What you'll do: Own core backend systems for Inworld Router — an intelligent routing layer across 200+ LLMs with multi-provider failover, cost/latency-based routing, and real-time observability at massive scale Build and scale API-based model services (TTS, STT, LLM, Knowledge/RAG) powering consumer-facing AI applications with hundreds of millions of end users Design and implement realtime, low-latency systems for speech-to-speech and Realtime API products Collaborate closely with PMs, engineers, and sibling ML teams to determine the biggest product needs and ship quickly in a rapidly evolving AI landscape Drive system improvements and advocate for new technical standards, dependencies, and architectural decisions with considerable technical autonomy Work on ambitious new products launching later this year, including platformization of new offerings and system-wide infrastructure projects Key context: This is a pure IC role — no management responsibilities, but strong ownership expected Flat team structure reporting to the VP of Engineering (~7-8 person team) AI tools and agents are embraced in the development workflow and interview process Startup experience is strongly preferred — candidates from only large tech companies without any startup background are not a fit Adaptability across tools and languages is valued over deep specialization in a single language