The problem

Secure OTP auth for microservices

Python / gRPC / MongoDB / Redis / RabbitMQ / Docker

Architecture

Project architecture

Service architecture

Codebase

Clean architecture structure

Clean architecture layers

Auth flow

OTP login flow

OTP login flow

Extensibility

SMS provider strategy

SMS provider strategy

Token safety

Refresh token rotation

Refresh token rotation

Deployment

Production deployment

Production deployment

Tests

Coverage report

16 automated tests passing
OTP and token use cases
gRPC auth behavior
Demo BFF routes
SMS provider adapters
ruff, mypy, compose config

Outcome

Interview-ready microservice demo

A focused auth service with clean boundaries, secure OTP, async messaging, provider strategy, and production deployment posture.