Principal Engineer — Machine Learning

PayPal; San Jose (CA); Hybrid; USD 242,000 - 359,000; Full time

Job summary

PayPal is seeking a Senior Machine Learning Engineer to drive strategic ML initiatives, leading development of scalable models and deploying them into production to enhance services and customer experiences. You will collaborate with data scientists, software engineers, and product teams across PayPal's hybrid work environment in San Jose.

The role emphasizes building end-to-end ML pipelines, data quality assurance, and publishing innovative ML methodologies to advance PayPal’s AI capabilities.

Qualifications

• 10+ years of relevant ML experience or equivalent combo of education and work.
• Deep expertise with TensorFlow, PyTorch, or scikit-learn.
• Extensive experience with cloud platforms (AWS, Azure, GCP) and data/model deployment tools.
• Proven track record leading design and deployment of ML models.

Responsibilities

• Define and drive the strategic vision for ML initiatives spanning multiple teams or projects.
• Lead development and optimization of state-of-the-art ML models.
• Oversee preprocessing and analysis of large datasets.
• Deploy and maintain ML solutions in production environments.
• Collaborate with cross-functional teams to integrate ML models into products.
• Monitor performance of deployed models and iterate as needed.
• Mentor junior engineers and data scientists.
• Publish research findings and contribute to industry discussions.
• Lead development of new methodologies and frameworks for ML applications.

Skills

TensorFlow

PyTorch

scikit-learn

Cloud platforms

ML model deployment

Education

Bachelor’s degree or higher in a related field

Tools

AWS

Azure

GCP

BigQuery

Spark

Airflow

dbt

Job description

Company

PayPal has been revolutionizing commerce globally for more than 25 years. Creating innovative experiences that make moving money, selling, and shopping simple, personalized, and secure, PayPal empowers consumers and businesses in approximately 200 markets to join and thrive in the global economy.

We operate a global, two-sided network at scale that connects hundreds of millions of merchants and consumers. We help merchants and consumers connect, transact, and complete payments, whether they are online or in person. PayPal is more than a connection to third-party payment networks. We provide proprietary payment solutions accepted by merchants that enable the completion of payments on our platform on behalf of our customers.

We offer our customers the flexibility to use their accounts to purchase and receive payments for goods and services, as well as the ability to transfer and withdraw funds. We enable consumers to exchange funds more safely with merchants using a variety of funding sources, which may include a bank account, a PayPal or Venmo account balance, PayPal and Venmo branded credit products, a credit card, a debit card, certain cryptocurrencies, or other stored value products such as gift cards, and eligible credit card rewards. Our PayPal, Venmo, and Xoom products also make it safer and simpler for friends and family to transfer funds to each other.

We offer merchants an end-to-end payments solution that provides authorization and settlement capabilities, as well as instant access to funds and payouts. We also help merchants connect with their customers, process exchanges and returns, and manage risk. We enable consumers to engage in cross-border shopping and merchants to extend their global reach while reducing the complexity and friction involved in enabling cross-border trade.

Our beliefs are the foundation for how we conduct business every day. We live each day guided by our core values of Inclusion, Innovation, Collaboration, and Wellness. Together, our values ensure that we work together as one global team with our customers at the center of everything we do — and they push us to ensure we take care of ourselves, each other, and our communities.

Job Summary

This job will drive the strategic vision and development of cutting-edge machine learning models and algorithms to solve complex problems. You will work closely with data scientists, software engineers, and product teams to enhance services through innovative AI/ML solutions. Your role will involve building scalable ML pipelines, ensuring data quality, and deploying models into production environments to drive business insights and improve customer experiences.

Job Description

Essential Responsibilities

• Define and drive the strategic vision for machine learning initiatives across multiple teams or projects.
• Lead the development and optimization of state-of-the-art machine learning models.
• Oversee the preprocessing and analysis of large datasets.
• Deploy and maintain ML solutions in production environments.
• Collaborate with cross-functional teams to integrate ML models into products and services.
• Monitor and evaluate the performance of deployed models, making necessary adjustments.
• Mentor and guide junior engineers and data scientists.
• Publish research findings and contribute to industry discussions.
• Lead the development of new methodologies and frameworks for ML applications.

Minimum Qualifications

• 10+ years relevant experience and a Bachelor’s degree OR Any equivalent combination of education and experience.
• Deep expertise with ML frameworks like TensorFlow, PyTorch, or scikit-learn.
• Extensive experience with cloud platforms (AWS, Azure, GCP) and tools for data processing and model deployment.
• Proven track record of leading the design, implementation, and deployment of machine learning models.

Additional Responsibilities & Preferred Qualifications

• 10+ years in ML engineering, with deep expertise in recommendation systems, search ranking, or personalization at consumer scale
• Production experience with learning-to-rank, contextual bandits, or real-time recommendation systems serving millions of users
• Track record building ML that drives business metrics — you think in terms of engagement, conversion, and retention, not just model accuracy
• Experience with social platform ML: feed ranking, social graph models, content discovery, or network growth — at a company where social interaction is core to the product
• Strong platform design skills — feature stores, model serving, experiment infrastructure
• Experience with graph-based ML: social graph embeddings, transaction graphs, or knowledge graphs
• Strong data engineering instincts — BigQuery, Spark, Airflow, dbt — you understand the full pipeline from raw data to model prediction

The base pay for this role will depend on where you work and the relevant experience and expertise you bring. The expected range of pay for this role by location is:Primary Location : Pay Range: San Jose, California : ($242,000.00 - $359,150.00 Annually)

Subsidiary

PayPal

Travel Percent

0

For the majority of employees, PayPal's balanced hybrid work model offers 3 days in the office for effective in-person collaboration and 2 days at your choice of either the PayPal office or your home workspace, ensuring that you equally have the benefits and conveniences of both locations.

Our Benefits

At PayPal, we’re committed to building an equitable and inclusive global economy. And we can’t do this without our most important asset-you. That’s why we offer comprehensive, choice-based programs, to support all aspects of personal wellbeing—physical, emotional, and financial—delivering meaningful value where it matters most.We strive to create a flexible, balanced work culture with a holistic approach to benefits, including generous paid time off, healthcare coverage for you and your family, and resources to create financial security and support your mental health.

Commitment to Diversity and Inclusion

PayPal provides equal employment opportunity (EEO) to all persons regardless of age, color, national origin, citizenship status, physical or mental disability, race, religion, creed, gender, sex, pregnancy, sexual orientation, gender identity and/or expression, genetic information, marital status, status with regard to public assistance, veteran status, or any other characteristic protected by federal, state, or local law. In addition, PayPal will provide reasonable accommodations for qualified individuals with disabilities. If you are unable to submit an application because of incompatible assistive technology or a disability, please contact us at [e-mail].

Belonging at PayPal

Our employees are central to advancing our mission, and we strive to create an environment where everyone can do their best work with a sense of purpose and belonging. Belonging at PayPal means creating a workplace with a sense of acceptance and security where all employees feel included and valued. We are proud to have a diverse workforce reflective of the merchants, consumers, and communities that we serve, and we continue to take tangible actions to cultivate inclusivity and belonging at PayPal.