Is is very important that our tools are available 24/7 and we can pro-actively react on potential issues. To ensure the availability of our solution is high, we use the monitoring tool-suite from New Relic. Not only can we use their application for free, they also support us with their Pro-bono program. Once or twice a year, they create a team to assist us and ensure we use their products the best way possible.
More about New Relic and how we monitor our platform can you read here: https://newrelic.com/blog/how-to-relic/sensing-clues-ngo-alerts-dashboards