Foursquare's company blog covers product launches, data and location features, platform changes, and engineering decisions like moving to OpenStreetMap.
HN links it for company announcements, notably the switch to OpenStreetMap after Google Maps pricing changes and the Time Machine visualization.
Foursquare went with OpenStreetMap though, and claim "while the new Google Maps API pricing was the reason we initially started looking into other solutions, we ultimately ended up switching because, after all our research and testing, OpenStreetMap and MapBox was simply the best fit for us."
http://blog.foursquare.com/2012/02/29/foursquare-is-joining-the-openstreetmap-movement-say-hi-to-pretty-new-maps/
They could be lying to cover a penny-pinching move, but I think they're telling the truth simply because Foursquare doesn't need particularly good geodata. It only needs for locations you visit to be fairly recognizable and locatable, it doesn't need to know that you can't do a u-turn or go that way up a one-way street or the exact location of a point to less than 1m accuracy. The only businesses it cares about it wants in its own dataset, not the map providers. Same story for Apple and its photo display or (going way back now) Yahoo/Flickr using OSM for geolocating photos in Iraq and China, Afghanistan etc. despite Yahoo having their own map team:
http://code.flickr.com/blog/2009/02/13/changelog-yahoo-updated-map-tiles-and-some-osm-ones/
This process has been going on for a while now, it's the traditional story of the open alternative eating the market from the bottom-upwards and accelerating as it gets wider use and improves in quality in a virtuous circle.
Some informative links, in case you haven't seen them already:
* http://www.quora.com/What-caused-Foursquares-downtime-on-October-4-2010
* http://blog.foursquare.com/2010/10/05/so-that-was-a-bummer/
* https://groups.google.com/group/mongodb-user/browse_thread/thread/66752f49af68619?pli=1
Someone on this thread suggested that Foursquare's performance problem is related to the calculation of badges. I'm not sure where this idea came from. I haven't seen any mention of the issue being related to badges in first or secondhand sources.
That said, Mongo DB's map/reduce operation would not be a reasonable solution at this time. Mongo DB's map/reduce performance is, at present, somewhat lacking because it runs via the javascript engine which is currently single threaded. I know there are plans to improve performance of Mongo DB's javascript engine by switching to V8, but I don't know if V8 is multithreaded.
Often design decisions that look bad in hindsight get baked in early. By the time you realize that an alternate design would yield better performance, there may be too much data to migrate so you just have to live with it.
Excellent question! I work on the data team here, and we work on a variety of projects. Some of our features rely on data from our applications, and so we help develop those features by building our data models. On the other hand, some other projects, like our recent infographic[1], are open-ended - you have the freedom to come up with your own hypotheses and test them against our data.
If you have a good background in data munging and analysis, it's incredibly fun work - a nice mix between the creativity of investigating problems that interest you and the rigor of data science.
[1] http://blog.foursquare.com/2011/06/20/holysmokes10millionpeople/
Other big players in this space not mentioned in the TC article are:
Reverbnation Gigfinder: http://blog.reverbnation.com/2010/06/15/gig-finder-the-largest-free-searchable-venue-database/
Foursquare Venues project (with some layer on top - hint, hint): http://blog.foursquare.com/2011/03/14/1up-the-importance-of-platforms-and-how-we’re-extending-ours/
Indie On the Move: http://www.indieonthemove.com/
Venuetastic - YC's "Ebay for venues," and taking a cue from AirBnB.
These guys are positioning to be the Ebay of transportation: http://www.uship.com/
Links about Foursquare's problems with MongoDB. The site was down for a while when their 1.6 instance crashed:
* http://blog.foursquare.com/2010/10/05/so-that-was-a-bummer/
* http://www.infoq.com/news/2010/10/4square_mongodb_outage
* http://groups.google.com/group/mongodb-user/browse_thread/thread/528a94f287e9d77e?pli=1
I like MongoDB, it is easy to setup, work with and to understand. I think it has an opportunity to become the mysql of nosql (in more ways than one)
Foursquare and 10gen (the makers of MongoDB) share USV as an investor.
We changed the url from [1] because although that's a more original source, the Verge article seems a lot more substantive. We then buried [2] as a duplicate.
Those of you arguing for a thread-merging feature on HN will find this a juicy example for your cause. (Edit: which I'm also slowly becoming convinced of.)
1. http://blog.foursquare.com/post/84422758243/a-look-into-the-future-of-foursquare-including-a-new
2. https://news.ycombinator.com/item?id=7679771