Migrating from Underscore to Lodash

Modernizing the front-end stack

The core Dropbox web application is 10 years old and used by millions of users per day. Hundreds of front-end engineers across multiple cities actively work on it. Unsurprisingly, our codebase is very large and somewhat irregular. Recently written parts have thorough test coverage, other parts haven’t been updated in years.

Over the past two years we’ve worked to modernize our front-end stack. We’ve successfully moved from CoffeeScript to TypeScript, from jQuery to React, and from a custom Flux implementation to Redux. Having completed these migrations we identified our utility library, Underscore, as one more candidate for migration.

Read more

Improving Document Preview Performance

Introduction

Ever open a file on dropbox.com, or click a shared link your coworker sent you? Chances are you didn’t need to download the file to see it—you saw it right in the browser. This is the work of the Previews team at Dropbox.

Previews are part of the core Dropbox experience. They allow architects to access their entire portfolios on dropbox.com while at the job site to show their work. Designers can send work-in-progress to clients without worrying about whether they have the correct software installed. Office managers can review, comment, and annotate new office design proposals,

Read more

Optimizing web servers for high throughput and low latency


This is an expanded version of my talk at NginxConf 2017 on September 6, 2017. As an SRE on the Dropbox Traffic Team, I’m responsible for our Edge network: its reliability, performance, and efficiency. The Dropbox edge network is an nginx-based proxy tier designed to handle both latency-sensitive metadata transactions and high-throughput data transfers. In a system that is handling tens of gigabits per second while simultaneously processing tens of thousands latency-sensitive transactions, there are efficiency/performance optimizations throughout the proxy stack, from drivers and interrupts, through TCP/IP and kernel, to library, and application level tunings.

Read more

Deploying Brotli for static content

Introduction

Most representations of data contain a lot of redundancy, which provides an opportunity for greater communication efficiency by compressing the content. Compression is either built-in into the data format — like in the case of images, fonts, and videos — or provided by the transportation medium, e.g. the HTTP protocol has the Accept-Encoding / Content-Encoding header pair that allows clients and servers to agree on a preferred compression method. In practice though, most servers today only support gzip.

In this blog post, we are going to share our experiences with rolling out Brotli encoding for static content used by dropbox.com,

Read more

Annotations on Document Previews

Introduction

Location-specific feedback has always been fundamental to collaboration. At Dropbox, we’ve recognized this need and implemented annotations on document previews. Our goal was to allow users to provide focused and clear feedback by drawing rectangles and highlighting text on their documents. We ran into a few main challenges along the way: How do we ensure annotations can be drawn and rendered accurately on any kind of document, with any viewport size, and using any platform? How can we maintain isolation of user documents for security? How can we keep performance smooth and snappy?

Read more