ActiveJsonEntity: Bridging the gap between Rails and Java
We have a service-based architecture here at Wealthfront. Instead of our Rails layer talking to a database, it makes RPC calls over HTTP to a collection of services that send and receive JSON. Without a database we can’t use ActiveRecord, and all the niceties it provides. In their first incarnation, our models were plain Ruby… Read more
Move cash faster
I joined Wealthfront last week as a new engineer, and I recently wrapped up my first meaty development project within the backend trading system written in Java. The task was to modify the logic used for client withdrawals. Specifically, add logic to first pull from any incoming deposit money that is sitting in escrow, waiting… Read more
The first week at Wealthfront
I just finished my first week at Wealthfront. In my first three hours I fixed a small production bug. By the end of the week, I had shipped my first feature: the backend code to serve up the commit statistics feeding the visualization at our new engineering page. Moving this quick was empowering, and it… Read more
I can haz lambda on Java 7?
Superficially, lambda expressions in Java 8 are just syntactic sugar for instances anonymous inner classes. Syntactic sugar should not require classfile changes, so one might expect that code compiled with Java 8 lambdas could run on a Java 7 JRE. It turns out that you can’t do this, and not just because of an automatic… Read more
Reactive Charts with D3 and Reactive.js
New to Reactive.js? Check out last week’s introduction. All visualizations are ultimately a composition of smaller elements; data sets, scales, individual lines, and labels to name a few. Those elements relate to each other in different ways, and to manage their interdependency we typically find ourselves writing a master “render” method — something that can… Read more
A “Reactive” 3D Game Engine in Excel?
A great article over at Gamasutra outlines a toy 3D engine that uses a spreadsheet to do the calculations. Instead of the imperative approach, this “engine” is more functional-reactive. As mentioned in our post on Reactive.js the other day, Excel serves as a good metaphor when starting to grok functional reactive programming.