Check list for backend

Ensure that delete functionality for any record on page is asking for confirmation
Input fields should be checked for max field value. Input values greater than specified max limit should not be accepted or stored in the database
Check if downloadable files are pointing to correct file paths
Check if application crash or unavailable pages are redirected to the error page
Check numeric input fields with character input values. Proper validation message should appear
Verify that the user is not allowed to submit a page twice by pressing submit button in quick succession
Input data with first and last position blank should be handled correctly
In date field check if start date is greater then end date.
Deleted data should be updated on the hit of URL

Check list for frontend

Ensure your website is responsive and provides a good user experience on mobile devices.
Optimize images, use browser caching, and minimize server response time to improve loading speed.
Secure your website with HTTPS to enhance user trust and gain a ranking boost from search engines.
Create and submit an XML sitemap to search engines to help them crawl and index your pages.
Use a robots.txt file to guide search engines on which pages to crawl and which to exclude.
Set canonical URLs to prevent duplicate content issues and guide search engines to the preferred version of a page.
Optimize meta titles and descriptions for each page with relevant keywords and a compelling call to action.
Use header tags to structure your content and signal its hierarchy to search engines.
Provide descriptive alt text for images to make them accessible to users and search engines.

Start by manually inspecting the website's input fields, URLs, and areas where user-generated content is displayed. Look for places where unvalidated or unsanitized data is being used. Try injecting simple scripts to see if they are executed.
Test all input fields (text boxes, text areas, etc.) with various payloads, including:
```
  <script>alert("XSS");</script>
  <img src=x onerror=alert("XSS")>
```
Manipulate URL parameters to see how the application handles them. For example:
```
https://example.com/page?parameter=<script>alert("XSS");</script>
```
Test how the application handles different HTTP methods (GET, POST, etc.) with payloads in request parameters and bodies.
Explore how the website handles cookies. Test if you can manipulate cookies and if they are properly secured.

Locate forms, search boxes, and any input fields that send data to the server.
Look for URL parameters that are used in database queries.
Enter a single quote (') into input fields or URL parameters and observe the response.
If an error message or unexpected behavior occurs, it might indicate a potential vulnerability.
Enter SQL keywords like SELECT, UNION, AND, OR, and others into input fields.
Observe if the application responds in a way that suggests it's interpreting your input as SQL code.
Test both numeric and non-numeric inputs to see if the application handles them differently.