Describe how the work of a web service that provides…

The work of the web service will be organized as follows:

Data source:
- Obtaining current exchange rates from multiple reliable sources (Central banks, major exchanges, currency exchange offices).
- Using APIs for automatic data retrieval.
Collection and aggregation:
- Regular parsing and data collection from each source.
- Structuring the obtained data in a unified format.
Algorithm for finding the best rate:
- Developing and applying an algorithm that compares rates from all sources for each currency pair.
- Considering commissions, spreads, or other additional conditions of exchange offices (if applicable).
- Ranking offers from most profitable to less profitable.
Data storage:
- A database for storing current and historical rate data.
- Optimizing the database for quick access and search.
Caching:
- Using caching mechanisms (Redis, Memcached) to store frequently requested data (e.g., current best rates) to speed up client responses.
API for the frontend:
- Developing RESTful API or GraphQL API for interaction with the client side (website, mobile app).
- The API should provide endpoints for:
  - Getting current best rates for selected pairs.
  - Viewing rate history.
  - Searching rates by specific currency pair.
Task scheduler (Cron jobs):
- Setting up periodic tasks for:
  - Regularly updating rates (e.g., every 5-15 minutes).
  - Clearing outdated data.
  - Performing other background processes.
Monitoring and logging:
- Monitoring systems to track service operability, data sources, performance.
- Active logging to track errors and issues.
Infrastructure:
- Choosing suitable server infrastructure (cloud or own server).
- Setting up scalability to handle increasing load.
Security:
- Protecting the API and database from unauthorized access.
- Encrypting data during transmission (HTTPS).

Example architecture diagram:

graph LR
    A[Data sources<br>(APIs, Parsers)] --> B(Collection and aggregation server)
    B --> C[Rate database]
    C --> D[Cache (Redis)]
    D --> E[API server / Backend]
    E --> F[Web application / Frontend]
    E --> G[Mobile application]
    H[Task scheduler<br>(Cron)] --> B
    H --> C
    I[Monitoring system] --> E
    J[Logging system] --> E

    %% Connections

    B --&gt; I
    B --&gt; J
    C --&gt; I
    C --&gt; J
    D --&gt; I
    D --&gt; J
    E --&gt; I
    E --&gt; J

Describe how the work of a web service that provides the most favorable exchange rate will be organized.