A simple bank account system which allows account creation, user authentication and balance deposit and withdraws.

This repo contains the Nx monorepo with all the packages needed to run the whole platform.

This was made for learning purposes and to deepen technical knowledge. For example to test the tradeoffs of using a serveless microsservice architecture, and for manual implementation of some concepts such as BFF Token Bearer.

1. Clone the repository:

git clone https://github.com/g-otn/otnpay.git
cd otnpay

2. Start docker compose

docker compose up

This will also build a image of the workspace locally, used by the worker services.

3. After startup, for now, you can access the API docs for each microsservice:
   • Auth: http://localhost:9010
   • Account: http://localhost:9510

TODO

TODO

TODO

1. Make sure the application is running using the docker compose setup

2. Choose a service and navigate to the load tests folder:

cd apps/service-auth/tests/load
# or
cd apps/account-service/tests/load

3. Choose and execute a load test type:

k6 run smoke.js
k6 run load.js
k6 run stress.js
k6 run spike.js

Please access the "Scalar API Reference", the web interface for API documentation hosted by the services:

• Auth: https://otnpay-auth-service.g0tn.workers.dev/scalar
• Balance: https://otnpay-account-service.g0tn.workers.dev/scalar

There you will find documented request/response bodies, status codes and generated examples.

curl https://otnpay-auth-service.g0tn.workers.dev/auth/signup \
  --request POST \
  --header 'Content-Type: application/json' \
  --data '{
  "email": "",
  "ownerName": "",
  "password": ""
}'

curl https://otnpay-auth-service.g0tn.workers.dev/auth/login \
  --request POST \
  --header 'Content-Type: application/json' \
  --data '{
  "email": "",
  "password": ""
}'

curl https://otnpay-auth-service.g0tn.workers.dev/auth/logout \
  --request POST \
  --header 'Content-Type: application/json' \
  --data '{
  "refreshToken": ""
}'

curl https://otnpay-auth-service.g0tn.workers.dev/auth/refresh \
  --request POST \
  --header 'Content-Type: application/json' \
  --data '{
  "refreshToken": ""
}'

curl https://otnpay-auth-service.g0tn.workers.dev/health

curl http://localhost:9510/accounts/deposit \
  --request POST \
  --header 'Content-Type: application/json' \
  --header 'Authorization: Bearer YOUR_SECRET_TOKEN' \
  --data '{
  "amount": ""
}'

curl http://localhost:9510/accounts/withdraw \
  --request POST \
  --header 'Content-Type: application/json' \
  --header 'Authorization: Bearer YOUR_SECRET_TOKEN' \
  --data '{
  "amount": ""
}'

curl http://localhost:9510/accounts/balance \
  --header 'Authorization: Bearer YOUR_SECRET_TOKEN'

curl http://localhost:9510/health

• This is optimized for a single region (not global)
• Microsservices implement hexagonal (ports and adapters) architecture
• We're using a BFF Token Handler pattern:
  • Backend For Frontend (BFF) exists so tokens can be stored securely.
    • Tokens will be saved on Redis
    • Similarly, this allows queue messages to be published and consumed without exposing secrets to the client.
  • Client will only know the BFF and the session cookie, and never interact with the tokens directly.
• HTTP proxy is required so serveless environments can access an external Redis instance. Upstash provides this already.
• Postgres connection pooler is there to ease the load on the DB since each request would be a different connection. Supabase provides this already.
• Account microsservice hashes the transaction payload to avoid repeated transactions and uses database transaction to avoid acting upon stale data.
• Account microsservice will consume and produce Queue messages