Senior Applied AI Engineer — Flexible Work Environment

Proofpoint; Colorado; On-site; USD 167,000 - 245,000; Full time

Job summary

Proofpoint seeks a Senior Applied AI Engineer to lead research from question to decision. You will frame the problem, run experiments, and help deploy results across hosted and self-hosted models, ensuring measurable agent behavior and production readiness.

You will mentor engineers, collaborate with cross-functional teams, and translate research into practical security AI solutions with strong Python, ML fundamentals, and Kubernetes-based workflows.

Qualifications

• PhD in Computer Science or related field.
• 5+ years building software and ML systems, with recent hands-on work on LLM systems that went past the prototype stage; 7+ years preferred.
• 3+ years of research experience.
• Experience with Claude Code, Cursor or similar, used daily, without lowering your standard for correctness and tests.
• Experience with third-party model APIs and open-weight models.
• Strong Python and ML fundamentals.
• Familiarity with Kubernetes inference platform, Flyte for orchestration, LiteLLM / Langfuse.
• Experience building agents that do real work and evaluating them over time.
• Experience getting strong results out of frontier models, hosted or self-hosted.
• Nice to have: fine-tuning/open-weight models, automated prompts, multi-GPU serving, security-focused experience, and open-source contributions.

Responsibilities

• Answer hard questions with evidence, run smallest experiments, and deliver actionable results.
• Build self-improving systems with evaluation loops and monitoring.
• Make agent behavior measurable with task suites and tradeoffs between quality, cost, and speed.
• Work across hosted and self-hosted models, choosing appropriate deployment paths.
• Improve build with coding agents and provide practical tooling for stakeholders.
• Turn stakeholder problems into research projects and extend prototypes to production.

Skills

Python

ML fundamentals

Agent development

Evaluation & benchmarking

Frontier models

Open-weight models

Prompt optimization

Multi-GPU serving

Cybersecurity relevance

Open-source contributions

Education

PhD in Computer Science or related field

Tools

Claude Code

Cursor

Kubernetes

Flyte

LiteLLM

Langfuse

Job description

Proofpoint seeks a Senior Applied AI Engineer to lead research from question to decision. You will frame the problem, run experiments, and help deploy results across hosted and self-hosted models, ensuring measurable agent behavior and production readiness.

You will mentor engineers, collaborate with cross-functional teams, and translate research into practical security AI solutions with strong Python, ML fundamentals, and Kubernetes-based workflows.