About this role
About the Role HubSpot's Agent Platform team is building Breeze Studio, a custom agent creation product that lets customers define, deploy, and improve AI agents inside HubSpot. As a Machine Learning Engineer on the Agent Orchestration ML team, you'll own the models and systems that determine whether those agents are any good. This is core ML work: prompt optimization, LLM evaluation, model fine-tuning, and inference infrastructure. What You'll Do
- Design and run experiments to improve agent quality: better tool use, better reasoning, better outputs, using frameworks like DSPy and VLLM
- Build and maintain evaluation infrastructure to measure what's working and catch regressions before customers do
- Optimize LLM inference: latency, cost, model routing, and quality tradeoffs
- Partner with product teams on model selection and performance benchmarking
- Work closely with product engineers and PMs to translate customer quality problems into ML hypotheses and solutions
- Own models end-to-end: from research and experimentation to production deployment What We're Looking For
- 5+ years of experience in a dedicated ML Engineer role (not ML-adjacent software engineering)
- Strong Python skills; experience with PyTorch, VLLM, DSPy or similar LLM optimization frameworks
- Hands-on experience working with large language models in production: prompt engineering, fine-tuning, evaluation, inference optimization
- Ability to move from ambiguous problem ("this agent isn't performing well") to experimental design to shipped improvement
- Comfort working with limited supervision in an early-stage product environment Compensation & Benefits
- Annual Cash Compensation Range: $155,900—$233,900 USD
- The cash compensation includes base salary, on-target commission, and annual bonus targets under HubSpot’s bonus plan for eligible roles
- In addition to cash compensation, some roles are eligible to participate in HubSpot’s equity plan to receive restricted stock units (RSUs)
- Some roles may also be eligible for overtime pay
- Benefits and compensation packages are tailored to skills, experience, qualifications, and other job-related reasons; learn more about HubSpot’s compensation philosophy and benefits