Staff Engineer jobs in United States, California, San Francisco

Essential Responsibilities:

• Delivers complete solutions spanning all phases of the Software Development Lifecycle (SDLC) (design, implementation, testing, delivery and operations), based on definitions from more senior roles.
• Advises immediate management on project-level issues
• Guides junior engineers
• Operates with little day-to-day supervision, making technical decisions based on knowledge of internal conventions and industry best practices
• Applies knowledge of technical best practices in making decisions

Expected Qualifications:

• 3+ years relevant experience and a Bachelor’s degree OR Any equivalent combination of education and experience.

Preferred Expertise:
Knowledgeable in IVR development and voice-based applications, including IVR solution design, voice recognition technologies, voice UX design, text-to-speech systems, and telephony API integrations.

Key Skills:

Backend: Java, Spring Boot, Spring WebFlux, Python
Frontend: Node.js, JavaScript, TypeScript, React.js, with testing tools such as Cypress, Playwright.
Architecture: Cloud-native systems, microservices, distributed systems, CI/CD pipelines, design patterns.
Machine Learning/Natural Language Processing a plus: Experience with frameworks like LangChain, LangGraph, and LangFlow, as well as techniques like prompt engineering, RAG, and observability in LLM applications.

Travel Percent:

The total compensation for this practice may include an annual performance bonus (or other incentive compensation, as applicable), equity, and medical, dental, vision, and other benefits. For more information, visit .

Our Benefits:

Any general requests for consideration of your skills, please

Essential Responsibilities:

• Lead and manage data science projects, ensuring timely delivery and alignment with business goals.
• Develop and maintain data models, algorithms, and reporting systems to support data analysis and decision-making.
• Analyze complex datasets to identify trends, patterns, and insights that drive strategic initiatives.
• Collaborate with cross-functional teams to understand data needs and provide actionable insights.
• Ensure data quality and integrity through regular audits and validation processes.
• Mentor and guide junior data scientists, fostering a culture of continuous learning and improvement.

Expected Qualifications:

• 5+ years relevant experience and a Bachelor’s degree OR Any equivalent combination of education and experience.

• At least 7 years of experience analyzing large, multi-dimensional data sets and synthesizing insights into actionable solutions
• At least 3 years of experience in managing analytics teams
• Data driven mindset with a Master’s or Ph.D. degree in any quantitative discipline such as Analytics, Engineering, Computer Science, Economics, Statistics or Mathematics
• Experience in Advanced Analytics: Causal Inference and ML models.
• Fluent in SQL and Python
• Experience analyzing very large, complex, multi-dimensional data set
• Experience with one or multiple of the following will be highly desirable; Jupyter Notebooks, Teradata, Hadoop/Hive, BigQuery
• Domain expertise in payments or other financial services
• Exceptional communication skills, both written and verbal, to influence cross-functional teams
• Prior work experience in a product analytics space would be highly valued
• A passion for problem-solving and comfort with ambiguity

Travel Percent:

The total compensation for this practice may include an annual performance bonus (or other incentive compensation, as applicable), equity, and medical, dental, vision, and other benefits. For more information, visit .

Belonging at PayPal:

Any general requests for consideration of your skills, please

• Gain hands-on experience working on real-world large language model (LLM) and machine learning projects within the domains of commerce, personalization, recommendation, and user behavior understanding.
• Assist in the fine-tuning, evaluation, and deployment of LLMs for tasks such as personalized recommendations, semantic search, and behavioral modeling.
• Collaborate with experienced engineers, data scientists, and product experts to translate business requirements into actionable LLM and ML-driven solutions.
• Analyze data, build prototypes, and explore new methodologies to improve the effectiveness of personalization and recommendation systems.
• Contribute to the development and documentation of LLM training pipelines and model evaluation frameworks, ensuring reproducibility and maintainability.
• Present findings and recommendations to stakeholders across the organization, highlighting the business impact of personalization and LLM applications.
• Network with talented professionals and gain valuable insights into the world of financial technology, personalization, and applied machine learning.

• Strong understanding of machine learning concepts, algorithms, and techniques (e.g., supervised learning, unsupervised learning, deep learning).
• Familiarity with large language models (e.g., GPT, LLaMA, Mistral) and techniques for fine-tuning, prompt engineering, or embeddings-based retrieval.
• Proven ability to work with Python, libraries like NumPy, Pandas, Scikit-learn, TensorFlow, PyTorch, and Hugging Face Transformers.
• Experience with data analysis, cleaning, and wrangling.
• Excellent communication, collaboration, and problem-solving skills.
• A passion for learning and exploring new technologies.
• Highly motivated and proactive with a strong work ethic.

Basic Requirements

• Currently pursuing a PhD in Computer Science, Machine Learning, Statistics, or a related field .

• Strong theoretical foundation in ML algorithms, optimization, and statistical learning theory .

• Demonstrated ability to implement and evaluate ML models using Python and libraries such as NumPy, Pandas, Scikit-learn, TensorFlow, and PyTorch .

• Experience conducting independent research , with publications in relevant ML/AI conferences or journals (preferred).

• Excellent communication and collaboration skills, with the ability to present research to both technical and non-technical audiences.

• Highly motivated, curious, and proactive in exploring new research directions.

Program Information and Requirements

• This is a Summer 2026 PhD Internship (Spring and Fall sessions are not available).

• Must be enrolled in a PhD program at an accredited university, returning to studies after the internship.

• Must reside in the U.S. during the program.

• Must be authorized to work in the U.S. for the duration of the internship.

The total compensation for this position may include an annual performance bonus (or other incentive compensation, as applicable), equity, and medical, dental, vision, and other benefits. For more information, visit .

The U.S. national hourly pay range for this role is $66/hour.

Our Benefits:

Any general requests for consideration of your skills, please

Essential Responsibilities:

• Delivers complete solutions spanning all phases of the Software Development Lifecycle (SDLC) (design, implementation, testing, delivery and operations), based on definitions from more senior roles.
• Advises immediate management on project-level issues
• Guides junior engineers
• Operates with little day-to-day supervision, making technical decisions based on knowledge of internal conventions and industry best practices
• Applies knowledge of technical best practices in making decisions

Expected Qualifications:

• 3+ years relevant experience and a Bachelor’s degree OR Any equivalent combination of education and experience.

Additional Responsibilities

• Proven experience performing both manual and automated testing for large-scale web applications, ensuring quality across frontend, backend, and data layers.

• Strong expertise in frontend and backend validation, including UI flows, APIs, and service-level integrations.

• Hands-on experience with modern automation frameworks such as Playwright or Cypress, with a deep understanding of test design and best practices for scalable web testing.

• Ability to design and build test automation frameworks from scratch, defining architecture, structure, and reusable components that accelerate team-wide adoption.

• Experience defining test strategies, coverage plans, and quality gates for complex features and distributed systems.

• Familiarity with continuous integration and delivery pipelines (e.g., Jenkins, GitHub Actions, CircleCI) to enable automated regression and continuous validation.

• Skilled in debugging and root-cause analysis, using browser developer tools, network inspection, and logs to troubleshoot issues across the full stack.

• Strong analytical and communication skills, with the ability to influence quality practices across engineering teams and advocate for release readiness.

Travel Percent:

The total compensation for this practice may include an annual performance bonus (or other incentive compensation, as applicable), equity, and medical, dental, vision, and other benefits. For more information, visit .

Our Benefits:

Any general requests for consideration of your skills, please

Essential Responsibilities:

• Lead the development and optimization of advanced 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.

Expected Qualifications:

• 5+ years relevant experience and a Bachelor’s degree OR Any equivalent combination of education and experience.
• Extensive experience with ML frameworks like TensorFlow, PyTorch, or scikit-learn.
• Expertise in cloud platforms (AWS, Azure, GCP) and tools for data processing and model deployment.

• Design, develop, and deploy autonomous AI agents capable of performing complex tasks across business workflows.

• Collaborate with cross-functional teams to integrate LLM-based systems into existing platforms and tools.

• Develop frameworks for goal-driven, multi-step reasoning anddecision-making inAI agents.

• Implement agent orchestration, including memory, planning, and tool-use capabilities.

• Monitor and optimize agent performance using data-driven metrics, ensuring scalability, reliability, and compliance.

• Stay updated with the latest developments in LLM, RAG, and agentic system architectures, applying best practices to product innovation.

Travel Percent:

The total compensation for this practice may include an annual performance bonus (or other incentive compensation, as applicable), equity, and medical, dental, vision, and other benefits. For more information, visit .

Belonging at PayPal:

Any general requests for consideration of your skills, please

Essential Responsibilities:

• Makes technical decisions affecting multiple teams, crossing organizational boundaries
• Establishes conventions & processes to be followed by other employees
• Actions determine the utilization of company resources (people, money, assets) and affect the effectiveness of the company
• Handles multiple, multi-team initiatives simultaneously, using judgement to prioritize among more issues than can be handled individually.
• Understands evolving industry capabilities & practices and can judiciously apply up--to-date information for optimal results
• Competent at communicating technical issues with non-technical audiences
• Spreads their behavior, principles, and knowledge as a means of improving technical results of other employees (via many means – modeling behavior, 1:1s, working sessions, quality documentation)
• Partners with product management, to ideate solutions to business problems & goals

Expected Qualifications:

• 8+ years relevant experience and a Bachelor’s degree OR Any equivalent combination of education and experience.

• Lead design/solution discussions with local and global stakeholders
• Mentor and coach junior engineers, own code quality, conduct code reviews
• Own implementation of amodule/application/product
• Participate in complex architectural discussions that involve multiple systems
• Identify anyproduct/functionality
• Drive integration efforts and lead critical work streams of strategic initiatives sponsored by senior executives
• Drive engineering excellency through CI/CD/automation
• Pro-active response in identifying and troubleshooting integration or technical issues.
• Drive engineering excellency by creating reusable, production-ready code
• Collaborate with cross functional engineering teams globally to drive and align on solutiondesign/implementation

• Minimum of 8+ years of experience
• Owned/acting as tech lead forcomponent/services/domains
• Experience in Node.js development using Express.js, Koa.js or other frameworks
• Expert knowledge in Java, Spring framework, REST, gRPC
• Experienced with asynchronous patterns and messaging frameworks (e.g. Kafka)
• Familiarity with other languages and technologies development, including Node, Hadoop, Spark, NoSQL Databases.
• Experience in various architecture design patterns, design and implementation of Financial Systems/Platforms such as Core Banking, Back-end Payment Hubs, Financial reconciliation and reporting
• Expertise in designing for reliability, availability, scalability and performance in highly regulated Financial Services industry preferred.
• Strong analytical and problem-solving skills.
• Ability to create structure and drive progress in an ambiguous environment
• Superb communication skills; ability to comfortably interact with tech and non-tech colleagues
• Demonstrated ability to scope, create and successfully deploy new strategy/ initiatives / capabilities
• Experience to interact with engineering teams from multiple geo-locations
• Fluent communicate in English
• Experience with front-end frameworks a plus

Travel Percent:

The total compensation for this practice may include an annual performance bonus (or other incentive compensation, as applicable), equity, and medical, dental, vision, and other benefits. For more information, visit .

Our Benefits:

Any general requests for consideration of your skills, please