Comment 8 for bug 571371

So, the web ui has direct access to the database, where as the desktop client goes through API servers. We've deployed more database servers, which is why the web ui is faster, and we're not fine-tuning the number of concurrent threads and optimal number of API servers to get the best performance.
Once we figure out the best set up, scaling is simply adding more hardware. The increase in users caught us off-guard, there has been a significant increase a month ahead of expected. Both a curse and a blessing, as you can see :)