The heart and soul of AdmitHub, one of my long-term clients, is real-time messaging. AdmitHub builds messaging products targeted at graduating high school seniors looking for guidance in the college application process.

During our time working together, I helped AdmitHub overcome many engineering obstacles related to their real-time messaging platform and increase the size their user base by a factor of ten and quadruple their average user engagement rates.

Twilio

AdmitHub’s primary medium of interaction with its users is via text message. They use a host of Twilio products to manage SMS communications, and while Twilio is a fantastic product, it doesn’t come without its rough edges.

In order to ensure that inbound text messages are never lost, I helped build out a “front-end” micro-service that sits between Twilio and AdmitHub’s application servers. The purpose of this additional layer was to store all incoming messages from Twilio and forward them along to a heavy-weight application server. By keeping the micro-service small and stateless, it could be quickly scaled up and down to meet rapidly changing load demands, while never missing a message.

The system has held up in both testing and real-world high-load situations (college fairs, product launches, etc…). With minimal hardware, the system has been shown to handle tens of thousands of concurrent messages while never missing a beat.

Facebook and Web

While text messaging was AdmitHub’s initial bread and butter, they quickly realized that students use a variety of messaging platforms.

In light of this, I helped AdmitHub unbraid their messaging system’s internal logic from the Twilio-specific transport code. By correctly architecting this abstraction, we were able to add additional messaging transports, such as a web messaging client and an integration with Facebook Messenger.

By expanding to new messaging mediums, AdmitHub was able to reduce the friction of communicating with students who were reluctant to provide their phone numbers.