Senior ML/NLP Engineer

About Us
👏 Team from OpenAI, DeepMind, NASA, GoogleX, Tesla, and 2 physicians: 6 exits, 2 IPOs.
🔥 Our model outperforms Claude, Gemini, and GPT-4.5 on clinical benchmarks.
📈 400+ healthcare orgs signed in 16 months.
⚡️ $25M raised from YC, Amity Ventures, Sequoia scouts, and more.
🌎 $1T+ market opportunity. We’re going after all of it.

About the Role
We are seeking a Senior ML/NLP Engineer to own Sully.ai’s knowledge retrieval and Search/RAG systems—critical components for delivering reliable, evidence-based answers to clinicians. You will architect NLP pipelines, fine-tune transformer models, and design retrieval-augmented generation (RAG) techniques that make our AI assistant smarter, faster, and more accurate. By owning this core backend, you will directly impact the trustworthiness of medical answers provided to doctors.

Key Responsibilities

• Architect and optimize NLP pipelines for intent detection, entity extraction, and dialogue management.

• Own the Search/RAG backend: design, build, and tune vector search indexes of medical texts for high recall/precision.

• Implement document ingestion pipelines to ensure fast, accurate knowledge retrieval.

• Integrate search results seamlessly into LLM prompts to improve evidence-based answers.

• Define evaluation metrics (e.g., F1, ROUGE, latency) and establish ML model CI/CD practices.

• Deploy scalable services with FastAPI and Kubernetes.

Hard Requirements

• 5+ years of experience in machine learning/NLP engineering.

• Strong expertise with information retrieval systems (e.g., Elasticsearch, OpenSearch, Pinecone, FAISS).

• Hands-on experience with transformer models (e.g., BERT, GPT) and RAG techniques.

• Skilled in production deployment (FastAPI, Kubernetes, Docker).

• Track record of designing evaluation frameworks and CI/CD for ML models.

Nice-to-Have

• Familiarity with biomedical or clinical text.

• Experience in large-scale search or recommendation systems.

• Background in healthcare AI or regulatory (HIPAA-compliant) environments.

First-Month Focus

• Audit existing search pipelines and evaluate retrieval quality.

• Stand up a repeatable ingestion → vectorization → retrieval pipeline for medical texts.

• Define key evaluation metrics and baseline benchmarks for retrieval/response quality.

Success OKRs (90 Days)

• Achieve measurable improvement in recall/precision of knowledge retrieval (>X% vs. baseline).

• Integrate RAG pipelines into live production workflows for real doctor interactions.

• Deliver a scalable framework for ongoing model evaluation and iteration.

Culture Fit

• Persistent, driven problem solver

• Willing to push back on leadership to defend quality/timelines

• Thrives in high-ambiguity, fast-paced startup environments

Why Join Sully.ai?
🔥 Shape the Future of Healthcare: Build category-defining partnerships that enable doctors to focus on saving lives.
📈 Early-Stage Impact: Join early and play a critical role in shaping our partnership roadmap and overall company growth.
🌎 Remote-First Culture: Work with a talented, mission-driven team in a flexible, remote environment.
💰 Competitive Compensation: Enjoy a competitive salary, equity, and the opportunity to make a real difference.
🏆 Solve Scalability Challenges: Tackle complex challenges in a rapidly growing company, driving impactful change in healthcare.

Sully.ai is an equal opportunity employer. In addition to EEO being the law, it is a policy that is fully consistent with our principles. All qualified applicants will receive consideration for employment without regard to status as a protected veteran or a qualified individual with a disability, or other protected status such as race, religion, color, national origin, sex, sexual orientation, gender identity, genetic information, pregnancy or age. Sully.ai prohibits any form of workplace harassment.