A.I. Engineer - Nullify

Job description

We're building the agent runtime that finds, validates, and prepares fixes for vulnerabilities automatically, while people retain judgment and merge control. That means solving real distributed-systems and reasoning problems, not gluing together prompts. What you'll do Build and harden Nullify's multi-provider agent runtime — turn loops, structured output, budget governance, checkpoint/resume for multi-hour runs. Design agents that reason about business logic and real application behavior, not just pattern-match against known signatures. Build and grow our evaluation harness — labelled test cases, scoring, regression tracking — so we can measure whether an agent got better or just got different. Own agents end-to-end: detection, validation, fix generation, and the judgment calls in between. What you bring Strong software engineering fundamentals — Go or Python, comfortable in production systems, not just notebooks. Experience building or operating LLM-based agents beyond a single prompt-response call: tool use, multi-step reasoning, retries, evals. A scientist's instinct for measuring whether something actually works before shipping it. Genuine interest in security — you don't need to be an expert yet, but you need to want to become one.