All the UX design heuristics apply also in Engineering, of course, and are based on the technical requirements of WCAG, but World Wide Web Consortium (W3C) published a document that focuses more on the Dev:
Heuristic 1: Provide alternative equivalents to make information suitable for auditive, visual, and tactile channels. In that way it is possible to follow the presentation even if a user has limitations with some senses, some cognitive limitations or the device cannot handle some media very well.
As text is easy to create and easy to transfer to almost any sense with the help of assistive technologies it can usually be used as an alternative to other media. For instance, assistive technology for a blind user can easily change an image with alternative text to voice or Braille format. With timed material, such as animations and video, the text often needs synchronization and therefore it might be easier to provide it also directly in audio. Section 3.1 explains more about alternative equivalents and their use.
Heuristic 2: Provide means to select equivalent content. Users should be provided flexible means to access the equivalent content in any combination that is most suitable for them because of their disabilities or the limitations of the used devices.
Normally these means are provided by user agents but also some languages provide switches for selecting content. If author provides the default selections, he should make sure that nothing in his design prevents flexible user control. Sometimes the defaults can also be automatically negotiated.
Heuristic 3:Provide user control for presentation by separating it from the rest of the content. This benefits users with disabilities or devices with limited capability.
For instance, a blind user may want to define that emphasized text is read in a louder voice, or a user with low vision can change the fonts to a larger size and use colors that have more contrast. This principle can be implemented by using style sheet technology. It is discussed more in Section 3.3.
Heuristic 4: Provide device independent interaction so that users with different input and output devices can easily get to all the available functionality.
This is often reached by using a user agent that can provide access to the functions by emulating mouse. However, it is good to provide shortcuts that get users to functions without any need to use mouse or spatial positioning. This is hardest when walking in a 3D world, but doing it might also help others not so familiar with 3D navigation with a mouse.
Heuristic 5: Provide semantics for structure. This helps provide alternative ways for user navigation and orientation. This can also help the use of alternative presentations. Use authoring tools that support this.
Semantics can be provided by using the elements of the language in a correct way and by describing the site and page navigation and the structured components with other available means. The languages usually include general grouping elements that can be used to add semantics. The other means include the use of class hierarchy and semantic languages, such as Resource Description Framework (RDF) . These are discussed in more detail in Section 3.5.
Heuristic 6: Provide reusable components. This helps users who use a media that makes it more laborious to compare the components.
Multimedia often contains application-defined components that are repeated several times. Especially graphics components might be repeated but also some video sequences or houses or other objects in a 3D model might contain the same elements. A user who is examining a structured image visually can do it much faster than a blind user navigating through the structure and the equivalent alternative explanations or even the graphical components. Reuse of components saves time as a model component can be examined only once.
And again, the majority of the WCAG 2.1 success criteria fit into Nielsen’s 10 Usability Heuristics, and this is something usually known by the Engineers.