It's hardly news that Twitter is experiencing growing pains, but a couple of items have appeared in recent days that shed some new light on just how bad they're getting.

Most prominently, Ariel Waldman posted a harrowing account of how Twitter rebuffed her demands for action against another user who was harrassing her in violation of its terms of service. Predictably, it prompted hard questions about the company's philosophy of customer service. Twitter's subsequent response that it is revising said terms of service is also drawing heat. Ariel notes in a followup post that much of the friction arises from an apparently ongoing dispute over whetherTwitter is a community, as its avid followers believe, or a "communications utility" that enjoys some immunity from legal liability as long as it doesn't get too involved with the messages it relays.

Meanwhile, TechCrunch's Nik Cubrilovic sheds some light on just how daunting the technical challenges are as Twitter tries to scale up, based on information from "an individual who is familiar with the technical problems at Twitter":

Some of the best web applications are able to efficiently solve very complex problems to produce simple results for users (Eg. Google). The success of these applications is due to the innovative efforts by developers to solve large technical challenges, where they have often had to break new ground for solutions. For Twitter to reach a similar point of reliability they too will need a very comprehensive, ground-breaking solution.

The source that I spoke to also commented on how ill-prepared the Twitter team were and are for their current and future challenges. The small team contains a handful of engineers, with only a person or two committed to infrastructure and architecture. He goes on to point out that at Digg the team for network and systems alone is bigger than the total engineering team at Twitter, and that at Digg they are lead [sic] by well-known "A-list rockstars".

A post on the Twitter Developer Blog acknowledges those challenges:

Twitter is, fundamentally, a messaging system. Twitter was not architected as a messaging system, however. For expediency's sake, Twitter was built with technologies and practices that are more appropriate to a content management system. Over the last year and a half we've tried to make our system behave like a messaging system as much as possible, but that's introduced a great deal of complexity and unpredictability. When we're in crisis mode, adding more instrumentation to help us navigate the web of interdependencies in our current architecture is often our primary recourse. This is, clearly, not optimal.

Our direction going forward is to replace our existing system, component-by-component, with parts that are designed from the ground up to meet the requirements that have emerged as Twitter has grown. First and foremost amongst those requirements is stability. We're planning for a gradual transition; our existing system will be maintained while new parts are built, and old parts swapped out for new as they're completed. The alternative - scrapping everything for "the big rewrite" - is untenable, particularly given our small (but growing!) engineering and operations team.

CNet's Charles Cooper offers his own "translation" of Twitter's mea culpa, which he interprets as proof that the problems are truly massive and the near-term outlook for end-users is bleak. "Flawed strategic thinking about what the service is and what it might become has put Twitter in a hole of its own making," Cooper comments.

Incidentally, more and more newspapers -- including the Seattle P-I -- are now on Twitter.