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Identifying Non-Heap Class Leaks

April 18, 2016

At Wealthfront, a significant portion of our backend applications are written in Java. The Java Virtual Machine (JVM) uses Garbage Collection (GC) for memory management, this forces us to pay close attention to its characteristics and behavior. Every JVM service we run accumulates JVM and application-level statistics, spools these metrics into a statsd server, and… Read more

Building Mobile A/B Testing Infrastructure

April 11, 2016

Twenty years ago, one would have hardly heard the phrase “A/B testing”. In 2000, Google served its first A/B test to determine the optimal number of search results to display. In 2011 alone, they ran 7000 A/B tests across their platforms. A/B testing has become the bread and butter of product decision-making for Silicon Valley… Read more

How We Avoid A/B Testing Errors with Shrinkage

October 29, 2015

At Wealthfront, we use A/B tests to make our services more effective, informative, and convenient. Each A/B test consists of two or more variants of a feature or design, which we expose to visitors at random until we have have enough data to infer which is better. In a previous post, we explained why we… Read more

Testing JavaScript Modules

October 13, 2015

In our previous post we outlined benefits of writing JavaScript in modules. One benefit we didn’t mention was how much more testable JavaScript modules are. In your test file you can require the module under test and let the require system import any dependencies. The goal of this post is to outline some of the… Read more

Advice for the Transition from College to Industry

September 29, 2015

The transition from college to industry came with quite a few surprises and lessons. Reflecting back on own my experience, I want to share a few insights I’ve gained. Additionally I want to share habits I formed during my undergraduate that transitioned well, as well as those that required significant changes in order to assimilate… Read more

Why We Use Bayesian Inference

September 01, 2015

At Wealthfront, we’re constantly experimenting with our products to make them better. Like other internet companies, we use a metrics-driven approach to test product changes. Each change is validated with an A/B test (hypothesis test), where we evaluate the change on a subset of clients by measuring its impact on some business metric, like the… Read more