What needs to be checked before releasing an application?

• Functional Testing:
  • All declared functions work according to requirements.
  • Key user scenarios pass without errors.
  • Integrations with external systems/services function correctly.
  • Data handling (creation, reading, updating, deletion) meets expectations.
• Non-Functional Testing:
  • Performance: Response time, throughput, load (stress, peaks).
  • Security:
    • Protection against SQL injections, XSS, CSRF.
    • Authentication and authorization checks.
    • Access control to confidential data.
    • Vulnerability analysis using scanners.
  • Usability:
    • Intuitive interface.
    • Compliance with UI/UX standards and design mockups.
    • Error handling and providing clear feedback to the user.
  • Accessibility:
    • Compliance with WCAG standards (if necessary).
    • Use of assistive technologies (screen readers, etc.).
    • Contrast, font size.
  • Compatibility:
    • Various operating systems and their versions.
    • Different browsers and their versions.
    • Different devices (screen resolutions, form factors).
• Regression Testing: Checking for the absence of new errors in previously working functionality after changes. Using automation for key regression sets.
• Localization and Internationalization Testing (applicable):
  • Correct display of texts in all supported languages.
  • Correct date, number, currency formats.
  • No issues with encodings.
• Installation and Update Testing (applicable):
  • Correct application installation.
  • Seamless update to a new version (user data preservation).
  • Ability to uninstall the application without leaving "residues".
• Cross-browser and cross-device testing: Checking the correct operation of the application on all declared platforms and devices.
• Data Validation: Checking correct processing of input data, including boundary and incorrect values.
• Logging and Monitoring:
  • Checking the presence and correctness of log entries.
  • Testing monitoring systems for timely problem detection.
• Documentation Review: Relevance of user and technical documentation.
• Code Review and Static Code Analysis: Identifying potential errors and improving code quality before testing.
• Smoke Testing: Quick check of the main, critically important functions of the application for operability in the deployment test environment.

Final UAT (User Acceptance Testing) stage with the participation of real users or customer representatives.