Sr Software Engineer

The 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:

As a Senior Software Engineer on PayPal’s Experimentation Platform (ELMO), you will design and build backend services and distributed systems that power experimentation at enterprise scale. You’ll own the architecture and implementation of high-throughput, low-latency systems that process billions of experiment evaluations per day. This role is backend-focused, requiring deep expertise in distributed systems, data-intensive platforms, and service design.

This job delivers complete solutions spanning all phases of the Software Development Lifecycle (SDLC). It involves advising management on project-level issues, guiding junior engineers, operating with little supervision, and applying knowledge of technical best practices.

Job Description:

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 Qualification:

Additional Responsibilities

• Lead the design and implementation of backend services and distributed systems supporting experimentation workflows at PayPal scale.
• Build fault-tolerant, high-performance APIs and data services that integrate with BigQuery and other analytics platforms.
• Drive end-to-end ownership of backend features, from architecture and implementation to deployment and operational support.
• Partner with Product, Data Science, and ML teams to evolve experimentation methodologies, scorecarding, and analytics integrations.
• Mentor engineers, conducting design/code reviews and fostering best practices for backend and distributed system development.
• Troubleshoot complex distributed system issues and implement sustainable, long-term fixes.
• Contribute to scaling experimentation capabilities across PayPal’s ecosystem (mobile, web, backend services).
• Identify platform gaps and propose backend-focused enhancements that improve reliability, scalability, and developer experience.

Preferred Quali