Open to opportunities

Sergei Stadnik

@sergeistadnik

Message

I build production autonomous agents, deterministic evaluation systems, and end-to-end LLM SaaS products.

United States

Message

What I'm looking for

I'm looking to build production AI agents and LLM applications where rigorous evaluation, security, reliable infrastructure, and measurable real-world outcomes matter.

I've built and shipped production AI products including ListingIQ, a multi-tenant SaaS that analyzes listings with Claude text and vision for 200+ paying customers.

At Itest, I design LLM and agent systems end to end—from architecture and evaluation to deployment and operational tooling. I built an agentic payments platform on Google's Agent Payments Protocol with KMS-signed mandates and 96% test coverage, deployed through Google Cloud Marketplace.

I focus on proving what agents actually did, not what they claim. My evaluation harnesses pair deterministic validators with multi-run agent trials, programmatic graders, adversarial testing, and reproducible configurations.

I've also built blockchain indexing and alerting infrastructure, LoRA fine-tuning pipelines, a BERT sentiment classifier, and multimodal vision analysis systems. I work across Python, TypeScript, cloud infrastructure, security, billing, and the operational foundations required to run SaaS products reliably.

Experience

Work history, roles, and key accomplishments

Current

AI Engineer

Current

Itest

Jan 2020 - Present (6 years 7 months)

Design and ship LLM and agent systems end to end, including architecture, evaluation, deployment, and production tooling. Built an agentic payments platform on Google's Agent Payments Protocol (AP2) with KMS-signed mandates and 96% test coverage, and deployed to Google Cloud Marketplace.