Senior Machine Learning Engineer

@ Flagship Pioneering, Inc.

Company Overview

Extuitive is a Flagship Pioneering–backed startup reimagining product innovation for the AI era. Our mission is to empower entrepreneurs and direct-to-consumer (D2C) brands with AI-driven tools that simplify, accelerate, and scale the launch of new products. Based in Cambridge, MA, we operate like a special ops unit—fast-moving, data-driven, and relentlessly focused on impact.

About the Role

As a Senior Machine Learning Engineer, you’ll be responsible for designing, building, and deploying the ML systems that power our platform. You will work across the full lifecycle—from problem framing, experimenting with models, and fine-tuning LLMs, to deploying them in production and monitoring performance. Additionally, you will influence architecture decisions, set ML best practices, and help define how AI shapes our product experience.

Responsibilities

• Build and Deploy ML Models: Translate product requirements into ML problems and develop models such as LLMs, embeddings, classifiers, and recommenders.
• Own the ML Pipeline End-to-End: Design data pipelines for collection, cleaning, feature engineering, and labeling; establish MLOps practices including CI/CD, reproducibility, and experiment tracking.
• Make Pragmatic Technical Decisions: Evaluate off-the-shelf APIs versus custom solutions based on speed, cost, and intellectual property considerations.
• Wear Multiple Hats: Contribute to DevOps, analytics, backend integration, and real-time customer-facing issues.

Requirements

• 5+ years of professional experience in applied machine learning.
• Master's degree in ML, Software Engineering, or equivalent experience.
• Strong background in Python and ML frameworks (PyTorch, Hugging Face, Scikit-learn, Torchtune, Deepspeed or equivalent).
• Experience with LLMs or recommendation systems in production environments.
• Solid understanding of data engineering, including pipelines, ETL, and feature stores.
• Familiarity with vector databases, embeddings, and real-time inference methodologies.
• Experience with cloud ML infrastructures (AWS/GCP/Azure) and GPU utilization.
• Proficiency in MLOps practices such as experiment tracking, model versioning, and monitoring.
• Ability to write clean, maintainable code and establish best practices.
• Comfortable working in a fast-paced startup environment with evolving priorities.

About Flagship Pioneering

Flagship Pioneering is a bioplatform innovation company that invents and builds platform companies, each with the potential for multiple products that transform human health or sustainability. Since 2000, Flagship has originated and fostered more than 100 scientific ventures, generating over $90 billion in aggregate value. The company has been recognized on FORTUNE’s “Change the World” list and Fast Company’s annual list of the World’s Most Innovative Companies.

Equal Opportunity

Flagship Pioneering and its ecosystem companies are committed to equal employment opportunity irrespective of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status. We value diverse backgrounds and transferable skills.

Note for Recruitment Agencies

Flagship Pioneering and its affiliated Flagship Lab companies (collectively, “FSP”) do not accept unsolicited resumes from any recruitment agency unless contacted by our internal Talent Acquisition team.

Key skills/competency

Senior Machine Learning Engineer, ML, Python, PyTorch, MLOps, data pipelines, cloud, LLM, recommendation, ETL