Machine Learning Engineer

Welcome to Crosby, the next generation Law Company

We're a team of technologists and legal experts collaborating closely to reimagine corporate legal services from the ground up. We build proprietary technology and human in the loop workflows to radically enhance the lawyer machine relationship. Our mission is to review complex documents faster than ever and with perfect quality

Crosby was founded by Ryan (Penn, Stanford Law, ex Cooley, former GC) and John (Penn M&T, ex Ramp, ex Google)

We believe:

• A great legal system is the watermark of a great society.

• Legal work is art and science. We are discovering the frontier between the two— codifying what can be systematized, and amplifying human expertise where judgment matters most.

• The right way to deploy AI in law isn’t by selling software. It’s by selling outcomes — higher-quality legal work, delivered faster and more efficiently

• In an in-person culture at our NYC office.

The Role

As an ML Engineer, you will be a full stack owner of the intelligent features that power the Crosby platform. You’ll be responsible for the entire lifecycle of an AI feature—from building the underlying systems to customizing the models that make them run. Your work will involve both robust system design and the pragmatic application of advanced machine learning techniques, including model fine tuning when necessary. This role is for a product minded engineer who knows how to get the most out of modern AI and is obsessed with shipping reliable, high impact features.

What You'll Do

• Build Core AI Systems: Design, build, and scale our primary AI features, including complex Retrieval Augmented Generation (RAG) pipelines and agentic workflows.

• Customize Models for Impact: Selectively fine tune and adapt language models to improve their performance on highly specific legal tasks where off the shelf solutions fall short

• Ensure Production Quality: Develop practical evaluation methods and monitoring systems to ensure the reliability, accuracy, and efficiency of our AI features in production

• Apply AI Pragmatically: Stay on the frontier of AI research and identify the most effective techniques and tools to solve immediate product challenges

• Collaborate to Ship: Work closely with product, backend, and our in house legal experts to deliver end to end solutions that make our users more effective

What We're Looking For

• Experience: 3+ years of professional software engineering experience, with a focus on building and shipping AI/ML powered products.

• Strong Engineering Foundation: Deep proficiency in Python and a proven ability to build scalable, production grade systems.

• Practical AI Skills: Hands on experience building with LLM APIs (ex: OpenAI, Anthropic) and familiarity with the entire ML project lifecycle

• Analytical and Pragmatic: You have a data driven approach to problem solving and a strong intuition for when to build a complex solution versus when to ship a simple one

• Product Focused: You are driven by user impact and skilled at making smart technical trade offs to deliver value quickly

• Ownership: You thrive on taking full responsibility for features, from initial concept through to deployment and iteration

Ideal Qualifications

• Hands on experience with fine tuning language models

• Experience building and optimizing vector search systems (pgvector, etc.)

• Familiarity with deep learning frameworks like PyTorch, Jax

• Previous experience in a fast paced, early stage startup environment

Why Work at Crosby

• Foundational Impact: As a core member of the team, you will shape the intelligent systems, culture, and technical direction of the entire company

• Competitive salary and equity compensation

• Comprehensive health, dental, and vision insurance

• Unlimited PTO

• In person team in NYC with a collaborative, high energy environment.

Apply now to join Crosby and be part of transforming the legal landscape