Constraints

• Guidelines must be either followed or a rationale for breaking the guideline must be given in a comment nearby

UI

• UI should be hard to use wrong.
• User experience should only be disturbed when necessary.
• UI must be consistent:
  • Colors
  • Use toolbars
  • Reuse components (in storybook)
  • Keybindings
  • personified error messages
  • etc.

Rationale: to support main goal

Data Consistency

• Users always see the latest data.
• The data from the backend is the single source of truth. I.e., in conflicting scenarios always the backend takes preference.
• In offline scenarios either the backend gets locked or the frontend gets read-only.

Rationale: we prefer collaboration over offline use.

Backend

• We use REST with JSON
• API calls should be for interactive use and as such terminate within parts of a second, five seconds maximum, see Graceful Shutdown for more information.

Graceful Shutdown

Actix by default handles shutdowns (see here for reference).
As soon as the signal SIGTERM is issued to the backend no new connections will be accepted.

• Still running connection will be finished or terminated after 5sec.
• API requests should ideally take no longer than a few seconds, with a 5-second limit for logging and optimization purposes.
• Implementing this limit improves convenience for both developers (termination of endless loops) and continuous integration (faster restart on hanging API calls), with minimal complexity in the code.