The posting
OVERVIEW
Physical Superintelligence is a startup with roots at Google, NVIDIA, Harvard, Meta, MIT, Oxford, Johns Hopkins, Cambridge, and the Perimeter Institute building AI systems to discover new physics at scale. We are seeking an ML engineer to be the engineering arm of our researchers and teams: turn their code into systems that run at scale, and build and run the training and inference infrastructure those systems depend on.
Our mission is to discover and commercialize transformative physics breakthroughs at scale with artificial superintelligence, safely, verifiably, and for broad public benefit.
The last century's golden age of physics gave us transistors, lasers, and nuclear energy. We believe artificial superintelligence will unlock the next one. We're creating the infrastructure to industrialize scientific discovery and usher in this new era.
We have one product: new physics, at scale.
ROLE AND RESPONSIBILITIES
- Help researchers and the other teams with the engineering: turn research code into systems other people can run, with contracts, tests and an on-call owner.
- Build the services researchers use to launch runs, route across models and ship results, and be the first call when one breaks.
- Own the training and inference infrastructure those services run on: distributed jobs, GPU scheduling, model serving, on the shared platform Engineering runs.
- Go deep in one lane: distributed training, inference serving, the ML platform, or the gateway and agent infrastructure.
WHAT WE'RE LOOKING FOR
- Three or more years building and operating ML training or inference infrastructure in production, at a company that trains or serves models at meaningful scale. You have owned a system through a failure.
- Three or more years of software engineering on systems others depend on. You can build a service that other engineers and researchers depend on every day, with a contract, tests that catch a wrong answer, and a consumer who is not you.
- Depth in at least one of the following. We hire for one lane and expect you to learn the others on our platform:
- Distributed training: PyTorch DDP and FSDP, Ray or comparable, multi-node jobs; checkpointing and resume; where step time goes.
- LLM inference serving: vLLM, SGLang, Triton or comparable; batching, KV cache, quantization; an endpoint behind a gateway.
- ML platform and MLOps: Kubernetes GPU scheduling and preemption, experiment tracking, model and checkpoint registries, metering.
- LLM gateway, agent runtime and evaluation infrastructure: API proxying and provider routing with capture and metering; agent frameworks, sandboxes, memory and task registries; eval harnesses that run and grade agents at scale.
NICE TO HAVE
- Enough ML fluency to debug a training loop, a reward signal or inference-time behavior alongside a researcher.
- A second lane from the list above.
- GPU infrastructure, CUDA, or performance engineering for ML workloads.
- Cloud infrastructure (GCP, AWS) and infrastructure as code.
- Prior work embedded with a research team, turning research code into production systems.
HOW WE WORK
We hold a high technical bar and give people full ownership of their work, from spec to ship to on-call. We write contracts before logic, test against real systems instead of mocks, and favor simple designs that ship over clever ones that do not. Our development process is AI-native: we work with agentic coding tools daily, write specs that are legible to humans and agents alike, and lead with leverage.
LOCATION AND COMPENSATION
This role is hybrid, three days a week in person in our Cambridge, MA office. We offer competitive compensation including salary, benefits, and meaningful early-stage equity. We evaluate on technical breadth, systems thinking, ML infrastructure depth, and shipping velocity. We are an equal opportunity employer and value diverse perspectives in building platforms for AI-driven discovery.
Work Authorization: Candidates must be authorized to work in the United States. PSI is not able to sponsor or take over sponsorship of employment visas for this role, now or in the future.
Export Controls. PSI's work involves technology that may be subject to U.S. export control laws. To comply with those laws, PSI may require that the person in this role be a U.S. person, meaning a U.S. citizen or national, a lawful permanent resident, or an individual granted refugee or asylum status in the United States, or be eligible to receive any required U.S. government export authorization. PSI will confirm eligibility with each candidate in the same way, and only to the extent export control laws require.
Equal Opportunity. PSI is an equal opportunity employer and does not discriminate on the basis of citizenship status, national origin, or any other characteristic protected by law.
