Staff SW Engineer

Staff Software Engineer Full-time | San Francisco Introduction: Join us at Fastino as we build the next generation of LLMs. Our team, boasting alumni from Google Research, Apple, Stanford, and Cambridge, is on a mission to develop specialized, efficient AI. Fastino's GLiNER family of open source models has been downloaded more than 50 million times and is used by companies such as NVIDIA, Meta, and Airbnb Fastino has raised $25M (as featured in TechCrunch) through our seed round and is backed by leading investors including Microsoft, Khosla Ventures, Insight Partners, GitHub CEO Thomas Dohmke, Docker CEO Scott Johnston, and others.

What You’ll Work On: Help define the technical direction for Fastino’s platform, contributing to the architecture decisions that let us scale without slowing down. Design and build our agent harness, including the runtime loop, tool calling, context management, and error recovery, plus the eval harnesses that measure agent reliability. Build and scale our AI training and inference pipelines, pushing on latency, throughput, and cost as usage grows.

Own deployment of the Fastino platform into customer-managed AWS VPCs using Kubernetes and Terraform, including install, upgrade, and observability paths that work in environments we don’t control. Build secure sandboxed execution environments for agentic workloads on Modal Sandboxes. Ship full-stack features end-to-end while owning the hardest, most ambiguous problems on the team.

Partner closely with AI