# Sequence diagram
```mermaid
sequenceDiagram
autonumber
actor User
participant Web Service
participant Backend API
participant Database
User ->> Web Service: navigate to the landing page
Web Service ->>+ Backend API: [GET /profile] request profile for the user
Backend API ->>+ Database: query profile
Database ->>- Backend API: return profile
Backend API ->>- Web Service: return profile
Web Service ->> User: see the landing page
User ->> Web Service: Update profile
Web Service ->>+ Backend API: [POST /profile] Update user profile
Backend API ->>+ Database: Save profile to db
Database ->>- Backend API: return result
Backend API ->>- Web Service: return result
Web Service ->> User: see result
```
```plantuml
actor User
participant "Web Service" as web_service
box "Backend Service"
participant "Backend API" as api
database "Database" as db
end box
autonumber
autoactivate on
User -> web_service: navigate to the landing page
web_service -> api: [GET /profile] request profile for the user
api -> db: query profile
return return profile
return return profile
return see the landing page
User -> web_service: Update profile
web_service -> api: [POST /profile] Update user profile
api -> db: Save profile to db
return return result
return return result
return see result
```