SMS Identity & Tokenization Microservice
A US direct-to-consumer personal-care brand
Overview
A serverless identity microservice for a US direct-to-consumer personal-care brand. It receives inbound SMS messages, mints encrypted identity tokens, and returns short, trackable links so users can be onboarded into the brand’s mobile experience directly from a text message.
Why It Exists
The brand wanted a frictionless, phone-number-first way to bring people from an SMS touchpoint into its app and waitlist without forcing account creation up front. The service bridges the telephony layer and the application by turning a phone number into a secure, decryptable token embedded in a personalized link.
What We Built
A small set of HTTP-triggered serverless functions deployed via the Serverless Framework onto a Kubeless (Kubernetes-native) runtime. The core handler.js parses inbound Twilio webhook payloads, generates AES-256-CBC encrypted tokens from the user’s phone number, shortens the resulting onboarding URLs through the Bitly API, and exposes companion endpoints to decrypt tokens back into identity data. Twilio’s MessagingResponse (TwiML) is used to reply within the SMS conversation.
Technologies & Approach
Node.js on a Kubeless serverless provider, with the Serverless Framework managing deployment and the Twilio Serverless Runtime for local development. Cryptography is handled with Node’s native crypto module (AES-256-CBC with per-message IVs), HTTP calls via axios, and SMS handling via the Twilio SDK. The serverless-on-Kubernetes choice kept the identity layer cheap to run and independent of the main application stack.
Outcome / Impact
Delivered a self-contained identity and tokenization layer that connected an SMS marketing channel to the brand’s app onboarding. It validated a phone-first acquisition flow and demonstrated secure, stateless token exchange between telephony and application tiers.
Capabilities Demonstrated
- Designing lightweight serverless microservices on a Kubernetes-native runtime
- SMS / conversational onboarding via Twilio webhooks and TwiML
- Stateless, encrypted token-based identity exchange
- Integrating third-party APIs (Twilio, Bitly) into an event-driven flow