We’re using TTVC to measure performance on the web—and now you can too

We’ re using TTVC to measure performance on the Web—and now you can too

摘要

Nobody likes waiting for software. Snappy, responsive interfaces make us happy, and research shows there’s a relationship between responsiveness and attention1. But maintaining fast-feeling websites often requires tradeoffs. This might mean diverting resources from the development of new features, paying off technical debt, or other engineering work. The key to justifying such diversions is by connecting the dots between performance and business outcomes—something we can do through measurement.

Over the last year, we’ve been rethinking the way we track page load performance on the web at Dropbox. After identifying a few gaps in our existing metrics, we decided we needed a more objective, user-focused way to define page load performance so that we could more reliably and meaningfully compare experiences across products. We thought a relatively new page load metric called Time To Visually Complete (TTVC) could work well.

There was just one problem: Browsers don’t yet report the moment a page becomes visually complete. If we wanted to adopt TTVC as our new primary performance metric, we would have to fill that gap. So we built a small library to allow us to track TTVC as our users experience it in the real world. That library is @dropbox/ttvc—and we’re excited to be open-sourcing this work!