Research Fellowship - Mechanistic Interpretability

Job description

## **About *Vmax*** *Vmax* is an applied research lab developing AI capable of open-ended learning. We are building systems to exceed humans in all capacities by optimizing beyond the local maxima of learning from human expertise. ## About the role LLMs are fantastically powerful and there is a rapidly growing corpus of work devoted to understanding their internal representations and computations. We use the tools of mechanistic interpretability to enhance reinforcement learning by generating intrinsic rewards as a supplement or alternative to downstream human-generated verifiers. This 3 to 6 month fellowship is for PhD students or equivalent early-career researchers who want to work at the intersection of mechanistic interpretability and reinforcement learning. You will own a focused research project, work closely with Vmax technical staff, and contribute to research publications. ## Responsibilities - Develop mechanistic interpretability methods for understanding internal representations, features, circuits, and computations in language models and agents. - Investigate how model internals can be used to generate intrinsic rewards, auxiliary objectives, diagnostics, or training signals for reinforcement learning. - Design and run experiments that test whether interpretability-derived signals improve learning, exploration, generalization, robustness, or sample efficiency. - Compare internally derived rewards against baselines such as human-generated verifiers, reward models, task-level outcome rewards, and standard intrinsic motivation methods. - Use techniques such as probing, activation analysis, sparse autoencoders, causal interventions, feature attribution, or representation analysis to study model behavior. - Analyze failure modes, including reward hacking, spurious features, non-causal correlations, objective misspecification, and overfitting to narrow evaluation distributions. - Build research code, evaluation harnesses, and experimental infrastructure that make results reproducible and useful to the broader team. - Communicate research progress clearly through written updates, internal presentations, and final project outputs. ## Role Requirements - Currently enrolled in a PhD program in machine learning, computer science, artificial intelligence, computational neuroscience, mathematics, or a related technical field. Exceptional candidates with equivalent research experience may also be considered. - Track record of research excellence or strong research promise, demonstrated through publications, preprints, open-source work, technical projects, competitions, or publicly available artifacts. - Working understanding of reinforcement learning. - Familiarity with mechanistic interpretability, representation analysis, or empirical methods for understanding neural networks. - Strong programming ability in Python and experience with at least one major ML framework such as PyTorch or JAX. - Clear written and verbal communication of technical ideas. ## Nice to have - Experience with LLM post-training methods - Familiarity with intrinsic motivation, unsupervised RL, auxiliary objectives, representation learning for RL, or curiosity-driven learning. - Experience with scalable ML experimentation, distributed training, experiment tracking, or reproducible research infrastructure. - Interest in turning mechanistic understanding into practical training methods, rather than only analyzing models after training. ## **Role specific location policy** - This role is based in our San Francisco office; for exceptional candidates we are willing to consider a hybrid arrangement