To visualize request flows, see the Service Diagram.

accountingserviceGoProcesses incoming orders and count the sum of all orders (mock/).
adserviceJavaProvides text ads based on given context words.
cartservice.NETStores the items in the user’s shopping cart in Redis and retrieves it.
checkoutserviceGoRetrieves user cart, prepares order and orchestrates the payment, shipping and the email notification.
currencyserviceC++Converts one money amount to another currency. Uses real values fetched from European Central Bank. It’s the highest QPS service.
emailserviceRubySends users an order confirmation email (mock/).
frauddetectionserviceKotlinAnalyzes incoming orders and detects fraud attempts (mock/).
frontendJavaScriptExposes an HTTP server to serve the website. Does not require sign up / login and generates session IDs for all users automatically.
loadgeneratorPython/LocustContinuously sends requests imitating realistic user shopping flows to the frontend.
paymentserviceJavaScriptCharges the given credit card info (mock/) with the given amount and returns a transaction ID.
productcatalogserviceGoProvides the list of products from a JSON file and ability to search products and get individual products.
quoteservicePHPCalculates the shipping costs, based on the number of items to be shipped.
recommendationservicePythonRecommends other products based on what’s given in the cart.
shippingserviceRustGives shipping cost estimates based on the shopping cart. Ships items to the given address (mock/).