Research Engineer - Agency and Reasoning
- Level
- Mid
- Work type
- On-site · San Francisco
Not stated in the posting: salary, visa.
Open. First seen 2 October 2026.
About the role
Zyphra's standard text
Zyphra is an artificial intelligence company based in San Francisco, California.
The Role:
As a Research Engineer - Agency and Reasoning, you will be a core contributor to Zyphra’s Agency and Reasoning Team. You will be involved with performing novel research in reinforcement learning, post-training, and human preference learning, and applying your ideas at scale to our next generation of language models.
What We’re Looking For / Requirements:
- Strong research taste and intuition
- The ability to work through a research project from conception to execution to write-up
- Strong implementation and prototyping skillset
- A researcher who can take an idea from conception to experimentation extremely quickly
- The ability to work well and cooperate with others in a high-paced research setting
- Curiosity, interest, and joy in understanding intelligence.
Qualifications / Additional Skills:
- Experience and aptitude with reinforcement learning, either in the context of language model reasoning or more classical RL tasks
- Experience with language-model-supervised fine-tuning and preference-learning methods, such as DPO and simPO.
- Experience with context-length extension methods
- A good intuitive ability to understand model behaviors and correct them through iterative fine-tuning
- Interest in grappling in detail with data and spending significant time involved in data engineering and synthetic data generation
- Postgraduate degree in a scientific subject (Computer Science, EE/EECS, Mathematics, Physics)
- Previously published machine learning research in well-respected venues
- Highly proficient with PyTorch and Python
- We are excited and able to rapidly learn new fields and implement new ideas
- Excellent communication and collaboration skills, and can work effectively on both research and engineering implementation at scale
Why Work at Zyphra:
- Our research methodology is to make grounded, methodical steps toward ambitious goals. Both deep research and engineering excellence are equally valued
- We strongly value new and crazy ideas and are very willing to bet big on new ideas
- We move as quickly as we can; we aim to minimize the bar to impact as low as possible
- We all enjoy what we do and love discussing AI
Benefits and Perks:
- Comprehensive medical, dental, vision, and FSA plans
- Competitive compensation and 401(k) plan
- Relocation and immigration support on a case-by-case basis
- In-office snacks and meals provided
- Unlimited PTO and company holidays
- In-person team in San Francisco with a collaborative, high-energy environment
What this role asks for
In most of Zyphra's ads
Machine Learning · Python
Named in most of its open postings, whatever the role.
97% of this description is written for the role. The rest is Zyphra's standard text, folded away below.
Read against Zyphra's other open postings on this site.
The team: R&D - Engineering HIRES STEADILY
This role is one of 9 open in R&D - Engineering. 2 were posted in the last 30 days and the oldest in March: a team that hires all year rather than one being built.
WHAT THE TEAM WORKS WITH, ACROSS ITS POSTINGS
Machine Learning (8 of 9), Python (8 of 9), PyTorch (7 of 9), AWS (2 of 9), CUDA (2 of 9)
OTHER ROLES ON THIS TEAM
- Machine Learning Systems Administrator / DevOps Engineer: Training Clusters & Inference Cloud posted Oct 15
- Research Engineer -- Vision and Vision-Language Models posted Oct 14
- Research Engineer - Model Architectures posted Mar 17
- Research Engineer - Language Model Pre-Training posted Mar 17
- Research Engineer - Audio & Speech Models posted Mar 17
- Data Engineer - Multimodal Systems posted Mar 17
- Research Engineer - AI Performance & Kernel Optimization posted Mar 16
- Research Engineer - Brain Computer Interface Models posted Mar 16
From the team and dates on Zyphra's own job board.
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