The Hidden Cost of Convenience: Rethinking Old ORM Patterns for Scale
Ever been here before? Stuck with a job that needs to be continually revisited because its performance gets worse with every passing day, and each attempt at improving said performance yields diminishing returns? This is the situation we found ourselves in with the portfolio balance calculation system—the code responsible for aggregating data from multiple sources… Read more
Automating Exhaustive Branch Coverage for Sealed Types in Kotlin
We take code correctness and code quality seriously at Wealthfront. One of the most effective ways we ensure that our code is correct is through rigorous unit testing and strong typing. In Kotlin, sealed classes and sealed interfaces offer a powerful tool to model restricted class hierarchies. They provide strong guarantees about the types in… Read more
ValidUntil: Ensuring compile-time data integrity in our investing system
As a financial services company, it is paramount that our investing system makes decisions based on accurate, up-to-date, and valid data. A single bad input can lead to disastrous outcomes, including costly trading mistakes and a loss of client trust. At Wealthfront, we built a system called ValidUntil that allows engineers to have confidence that… Read more
Shipping Containers: How We Built an Easy to Use Jenkins Pipeline for ECR
The DevOps team at Wealthfront has been in the process of migrating services to run inside containers. As part of this process we need a way to build containers using our CI/CD tool, Jenkins. While we could write a Jenkinsfile for each container image we wanted to build, we identified this was a good opportunity… Read more
Going Edge-to-Edge: How Android SDK 35 Modernizes the Wealthfront App
One of our core engineering principles at Wealthfront is maintaining a high standard of quality and platform infrastructure, and that includes keeping our platforms up to date on the latest releases. On Android, this means keeping our targetSdk up to date, which provides Wealthfront’s Android users with the latest security and platform stability features, as… Read more
How I Wrote Code That Allocates Cash Account Interest Daily as a Wealthfront Intern
My first time walking into Wealthfront’s office wasn’t the first day of my internship. Instead, it was 4 months prior, when I was flown out to Palo Alto for the onsite interview. Wealthfront was the only company that flew me out for an in-person interview. And it was awesome. Not just because the people were… Read more