Lessons from Yahoo's iPad App in the Cloud

Remember newspapers? With Yahoo Entertainment's iPad app, you might not need to for very much longer. You'll find the lifestyle section (Dear Abby? It's got that) and more in the mashup that stretches across several Yahoo teams. And the way it was put together may offer a glimpse into the future of APIs and preparing content for multiple devices.

The iPad app brings together entertainment news, comic strips and TV listings--staples of most newspapers. It also includes content that doesn't work in print, such as video and interfaces to access only the data you want. You can see the app demoed by Mashable in the video embedded below.

Senior vice president of application development Sandeep Gupta led the team that created the app, which launched only six weeks after Apple announced the iPad. Most of the content already existed, so the team used YQL (our Yahoo Query Language API profile) to bring it together. "YQL allowed us to build custom queries for custom content delivery," Gupta said.

Yahoo also used its internal cloud storage solution, MObStor, which provides fast access to unstructured data. Along with video and other media, Yahoo stores pre-generated SQLite databases, which can be downloaded and installed directly on the iPad.

According to Gupta, downloading SQLite databases directly saves user time. It can take several minutes to index and create a database on the iPad, whereas the same could be created in 20 seconds on MObStor. "We try and do a lot of the heavy lifting in the cloud where it makes sense," Gupta said. A database of TV listings weighs in at 1-2 MB per day.

Gupta believes pre-processing data will become more commonplace and users will want more responsive interfaces that can't wait for individual API calls. Since many databases are too large to download in total, part of the trick is guessing what the user might do next and try to prepare that data.

And the lessons aren't just for the iPad. We used to say web interfaces were becoming more desktop-like. Maybe now they're becoming more like native apps. "HTML 5 has local storage, so theoretically any web app could take advantage of this in the same way," Gupta said.

Be sure to read the next Cloud article: Google Packs a Punch with Latest App Engine Release