# Machine Learning Engineer: LLM Interpretability & Systems
**Company:** [CTGT](https://hotfix.jobs/companies/ctgt)
**Location:** San Francisco, CA
**Salary:** $175K-$250K
**Skills:** PyTorch, Transformers, Mechanistic Interpretability, Activation Patching, Control Vectors, Feature Extraction, LLMs, Deep Learning, Fine-Tuning, Model Optimization
**Posted:** 2026-03-27
> Develops systems for LLM interpretability and deterministic governance by working directly with model weights, activations, and architectures. Implements mechanistic interpretability techniques like activation patching and control vectors for enterprise policy enforcement in production.
## Job Description
## 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.

## What We Offer
**Compensation & Equity:** Competitive base compensation, plus significant equity in a venture-backed company with institutional investors including Google’s Gradient Ventures, General Catalyst, and Y Combinator. We want people who think and act like owners.
**Real Impact:** You will work directly on the core systems that determine how models perform in the wild. Your work ships into real, high-stakes environments where governance, auditability, and performance are non-negotiable.
**Autonomy & Trust:** We operate with a high degree of trust. You are expected to form strong technical opinions and execute on them.
**Apply:** https://hotfix.jobs/jobs/machine-learning-engineer-llm-interpretability-systems-at-ctgt-f303568d-1b64-4479-ba68-4bffcbc8d460
**Canonical:** https://hotfix.jobs/jobs/machine-learning-engineer-llm-interpretability-systems-at-ctgt-f303568d-1b64-4479-ba68-4bffcbc8d460