Job description
Senior AI Researcher (Post-Training)
Boston, Massachusetts (Hybrid / Remote)
$180,000 - $250,000 + Equity + Healthcare + PTO
Are you a Senior AI Researcher with a strong background in post-training language models looking to lead original research on autonomous, long-horizon agent systems within a high-growth cybersecurity startup?
This is an opportunity to join a fast-growing AI company developing next-generation autonomous offensive security platforms. You will become the company's first dedicated AI Researcher, working alongside engineering leadership and a specialized AI team to advance proprietary core models that reason, plan, and operate autonomously.
In this role, you will drive original research on offensive security agents, focusing heavily on post-training pipelines, reinforcement learning from verifier signals, and co-evolutionary self-training architectures. This is a pure research role with a fast feedback loop, where you will design end-to-end experiments and translate research wins directly into production-ready capabilities.
This role would suit an experienced AI Researcher who excels at building rigorous evaluation infrastructure from scratch and wants to pioneer how agentic systems behave under adversarial conditions.
The Role:
*Drive original research on agent reasoning, planning, and long-horizon execution *Advance post-training pipelines using supervised fine-tuning and reinforcement learning *Extend co-evolutionary self-training architectures and reward modeling systems
*Design end-to-end experiments and build custom evaluation harnesses
*Translate research breakthroughs into production handoffs for the engineering team
The Person:
*Proven track record of original machine learning research output or shipped systems *Hands-on post-training experience with large-scale language models (7B+ parameters) *Experience with reinforcement learning from verifier signals or preference optimization *Strong Python and PyTorch skills with multi-GPU distributed training experience
*US Citizen
Reference Number: BBBH275587
To apply for this role or to be considered for further roles, please click "Apply Now" or contact Ben Herridge at Rise Technical Recruitment.
Rise Technical Recruitment Inc of 1011 Centre Rd, Suite 322, Wilmington, DE 19805 act as an employer-paid private personnel agency.
The salary advertised is the bracket available for this position. The actual salary paid will be dependent on your level of experience, qualifications and skill set and will be decided by our client, the employer. Rise are not responsible or liable for any hiring decisions made by the end client.
We are an equal opportunities company and welcome applications from all suitable candidates.
