Kalibrr

We have our own special Hubot instance named kbot, that does everything from reminding us what to do, showing cat and corgi images, and notifying us of system errors. Hubot

All file uploads go straight to Amazon S3 (with maybe some preprocessing). Amazon S3's cheap and easy-to-use, with no need to worry about disk space limits. Amazon S3

We fall back to Nexmo when Chikka (https://api.chikka.com) and Semaphore (http://semaphore.co) have downtime or deliverability problems. Chikka and Semaphore are local (Philippine) SMS APIs handled by SMART and Globe, respectively, and report higher deliverability rates than Nexmo (at lower cost). Nexmo

Our internal emails (such as exception notifications) are sent via Amazon SES, since it's cheaper than using Sendgrid. We also use Amazon SES as a fallback in case we have deliverability issues with Sendgrid. Amazon SES

Server and application metrics are all stored in InfluxDB for capacity planning and anomaly detection. InfluxDB

We load balance our ElasticSearch cluster using HAProxy. The health checks come in handy. HAProxy

All of our servers are provisioned by Ansible, with no manual provisioning involved. This lets us easily roll out new servers, with no chance for human error when configuring the servers. We use the same code to provision local development environments on Vagrant, which eliminates configuration discrepancies between development and production. Ansible

Amazon Route 53 is a convenient way to manage our DNS routes. We just use the web UI for now, since we don't have any complex DNS setups. Amazon Route 53

All of our external emails are sent using SendGrid. SendGrid's statistics dashboards help us figure out whether our emails are reaching people, and how much attention is paid to them. SendGrid

All of our servers are hosted on Linode, which scored better in our benchmarks, and are significantly cheaper than EC2 instances. Linode