Interning @ PayPal: Checkout A/B Testing, Developing Features, and Cracking Bugs

PayPal Tech Blog Team
The PayPal Technology Blog
3 min readAug 1, 2016


My internship at PayPal was a great experience. I was given real work that mattered. From day one, I had the opportunity to continuously write, commit, and push production level code that impacted the millions of people who use PayPal Checkout.

As a Software Engineering Intern on PayPal’s Checkout Guest and Signup team, I focused on building and iterating A/B tests to improve customers’ experiences and onboard new users. Within a few weeks of joining, I developed a solid enough understanding of our frontend and backend codebase to fix several critical production bugs: everything from updating password tooltip feedback to risk validation fixes. I was able to simultaneously work with design and product on implementing new features, fixing bugs, and iterating on A/B tests, all of which have been pushed to live.

Ex: A Simple Date of Birth Tooltip UI Upgrade


With one of our rockstar engineers, Ming Jin, I worked on an A/B test feature: Web Payments Standard Interstitial, which is a specific checkout experience to convert a guest user to a signed up user. I was able to spend a lot of time on this test, repeatedly pushing code as we kept ramping variant frequency.

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In my last few weeks, among all the intern event madness and winning 2nd place at an internal dashboard hackathon, I didn’t know what else I would tackle.

After those event packed weeks, I started working on another A/B test that incentivized user signup to an even deeper level of regular AB tests by running text variants on these A/B tests themselves.

Working at a large company like PayPal, I realized that I had the chance to make a significant impact on on-boarding users through these A/B tests, even if impact seemed minuscule at first. Ramping our tests up and down, I began to saw the impact of my work as conversion rates would show up high after a successful release cycle.

I was fortunate enough to be included in the team’s work to the extent that I was able to work on the other side of code reviews: the side where I review other people’s code! This absolutely blew my mind! I never thought I would be reviewing other engineers’ code as an intern. My opinion was valued, my knowledge on the codebase was trusted, and my work ethic was recognized as one that really championed for the best possible product.

I feel really proud of what I accomplished this summer, especially after being recognized for my high performance. The impact of my work didn’t hit me until I bought a gift on Etsy and the beautiful experiences I helped curate showed up on my screen.

Shout out to my main mentors Vikram Somu, Karthik Chandrakanth, and Ming Jin for taking the time to guide me on all the things I did. Also thanks to Shruti Jain, Viswa Nachiappan, and Upendra Pigilam for being great team members and mentors. Finally, thanks to my manager, Stephen Westhafer, for ensuring I had the resources and guidance I needed to be successful! As a team, we had great moments: everything from office email pranks to pushing a successful release.

In addition, thanks to Mark Stuart and Daniel Brain for helping me on a variety of things from contributing open source to pushing this blog post.

You’ll see my work the next time you checkout with PayPal!