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