Principal Machine Learning Engineer

Hims & Hers•,

1d•$180,000 - $200,000

About The Position

Hims & Hers is hiring a Principal Machine Learning Engineer to define and drive the architectural vision for large-scale foundational machine learning models and applications. The role focuses on systems that support care personalization, treatment intelligence, and automation, with impact across patient care, including the company’s AI-powered MedMatch system. The engineer will architect resilient, scalable, and extensible ML platforms that accelerate product development, enable intelligent care delivery, and shape long-term ML strategy and engineering practices across teams. The position combines hands-on technical work with cross-organizational technical leadership. It includes prototyping and guiding complex model pipelines and platform components, evolving infrastructure for training and real-time inference, aligning technical decisions with product strategy, setting quality and operational standards, and mentoring senior and staff engineers. The posting describes the company’s talent-first flexible/remote work approach but does not specify a work arrangement for this role.

Requirements

10+ years of experience in Machine Learning and/or Engineering, with a strong track record of technical leadership and system architecture across teams or business areas.
Expert-level proficiency in Python and advanced ML frameworks such as PyTorch or TensorFlow.
Demonstrated success designing, scaling, and evolving ML platforms for production-grade training, deployment, real-time inference, and monitoring.
Deep experience in LLMs and NLP, including transformer models, summarization, conversational agents, and embedding-based retrieval.
Advanced understanding of ML infrastructure, including continuous training, system observability, performance optimization, and platform reliability.
Experience with ML infrastructure tools such as Databricks, MLFlow, SageMaker, or equivalent.
Exceptional communication and cross-organizational leadership skills, including the ability to align technical and non-technical stakeholders around ML strategy and long-term architecture.

Nice To Haves

A Master’s degree or PhD in Computer Science, Machine Learning, or a related field; the posting states this is not strictly required.

Responsibilities

Define and drive the architectural vision for ML and LLM systems supporting treatment recommendation, personalization, and intelligent care delivery at scale.
Establish foundational design patterns and infrastructure practices to ensure systems are scalable, resilient, secure, and maintainable.
Use Python and ML frameworks such as PyTorch to prototype, optimize, and guide implementation of complex model pipelines and platform components.
Partner with platform, product, and clinical teams to align high-impact technical decisions with long-term product strategy.
Architect and evolve ML infrastructure for continuous training, real-time inference, evaluation, and observability.
Lead cross-functional initiatives that simplify system complexity, improve developer velocity, and increase organizational leverage.
Define cross-team standards for testing, observability, performance, and operational risk.
Mentor senior and staff engineers, supporting their development as systems thinkers and technical leaders.
Promote sustainable speed, system ownership, and architectural clarity across product and platform teams.