CalyptusAbout this role
About this opportunity
This role is being recruited by Calyptus on behalf of one of our clients.
Calyptus is a specialist recruitment partner helping startups and high-growth technology companies hire across engineering, product and design.
What to expect
We’ll review your application and, if your experience is a strong match, one of our team will be in touchWe’ll support you throughout the interview process and keep you updated at each stageIf this particular role isn’t the right fit, we may consider you for other relevant opportunities with our clients______________________________________________________
A new open-source model is released and you are compelled to reach inside and understand how it actually works. You instinctively try to push it beyond what most people say is already impressive. You observe model behavior and don’t think, “What’s a better prompt?”, but “How do I improve its fundamentals?”
Our Senior Machine Learning Engineer will operate deep within the model stack, working directly with weights, activations, and architectures to build the systems that make AI governance deterministic. Your work powers the Policy Engine, the core technology that gives enterprises real-time, auditable control over model behavior in production. Your mandate is ostensibly simple but difficult in execution: determine how a model can be improved for a specific purpose and build the systems that operationalize that within our platform.
As opposed to simply using models, you will probe the mechanics of their cognition.
What You Will Do
Take ideas from mechanistic interpretability and related work and turn them into code that runs in production, making research into reality.Work directly with model internals to improve behavior and performance across commercial and open-source models.Leverage techniques like activation patching, control vectors, and feature extraction to achieve targeted, repeatable improvements in model output.Build the evaluation and deployment loops needed to ship changes reliably into enterprise environments.Design and optimize the feature-level intervention systems that enable deterministic policy enforcement at inference time.
Who You Are
Strong understanding of Transformer architectures, PyTorch internals, and the mathematical foundations of deep learning.Have trained, fine-tuned, or optimized models beyond superficial augmentation.Can read a paper, decide what matters, and implement it.Notice when something is not working and take ownership of fixing it.Motivated by the challenge of making large language models reliable and controllable enough for the highest-stakes enterprise applications.
Our Stack
Languages: Python, Rust, and Node/TypeScript, with React on the frontendData: Postgresql, vector, and graph databasesInfra: Docker, Kubernetes, Terraform, across several cloud providers and customer VPCsML: Self hosted models on multiple GPU providers and frontier APIs
______________________________________________________
Genuine opportunities
Every role advertised by Calyptus is a live position we’re actively recruiting for. Some clients prefer to remain confidential during the early stages of the hiring process. When that’s the case, certain company details may be shared later in the process.
Why work with Calyptus?
Access opportunities with ambitious startups and high-growth technology companiesDirect support from experienced specialist recruitersHonest feedback and clear communication throughout the hiring processLong-term career support, not just a single job application
We look forward to hearing from you.
Company:
Calyptus
Level of experience (years):
Senior (5+ years of experience)
How to apply:
Please mention NLP People as a source when applying