Ask HN: What application performance & monitoring tools does your startup use?

Hi HN,

Recently launched a new startup and we were looking at tools for monitoring and keeping up to date with our app's performance.

Some googling led me to newrelic.com which has been a really awesome - and I am considering making the switch to a paid account. I just wanted to get a feel for what other startups are using before i hit the purchase button.

Thanks!