The type of operating system and hosting doesn’t matter much for design, but the platform is a factor. For instance, if you need a WordPress theme, the designer must work with WordPress themes and customize them in a way that a developer can feasibly code in CSS or JavaScript on the front end. If you use another CMS, the developer must work with those elements. Most designers specialize in specific platforms, so review their portfolios and experience for specific platforms before you invite them to bid on your project.
Until the ADA is updated to address the special case of website accessibility, or the Department of Justice releases its website accessibility regulations, complying with WCAG 2.0 Level AA is the best way to ensure that people with disabilities have equal access to your website. The overview below is a great starting point about meeting the WCAG 2.0 Level AA recommendations.

If your lawyer can’t negotiate a successful outcome directly with the other party, you’ll probably need to file a claim with your state’s fair employment agency, the EEOC, or the Department of Justice. A lawyer will make sure that you meet these agencies’ strict filing deadlines and help you present the most persuasive case possible. And if you need to file a lawsuit in court, hiring a lawyer will give you the best chances of success.
The words in the tag should be more than a description. They should provide a text equivalent of the image. In other words, the tag should include the same meaningful information that other users obtain by looking at the image. In the example of the mayor’s picture, adding an “alt” tag with the words “Photograph of Mayor Jane Smith” provides a meaningful description.
The ADA is the Americans with Disabilities Act, passed almost 30 years ago in 1990. This act was originally put in motion pertaining solely to physical location. It requires establishments to provide people with disabilities easy access to various levels throughout the business. This act was set to achieve an equal experience to all people, handicapped or not.
State and local governments will often post documents on their websites using Portable Document Format (PDF). But PDF documents, or those in other image based formats, are often not accessible to blind people who use screen readers and people with low vision who use text enlargement programs or different color and font settings to read computer displays.
Distinguishable: To assist color-blind users and those with other visual impairments, color is never used as the sole means of conveying information or prompting the user. Audio lasting more than 3 seconds can be paused, or the volume can be controlled independently of the system volume. Regular text has a contrast ratio of at least 4.5:1, and large text has a contrast ratio of at least 3:1. In addition, text can be resized up to 200 percent without causing issues with the website.
Many members of the business community opposed the Americans with Disabilities Act. Testifying before Congress, Greyhound Bus Lines stated that the act had the potential to "deprive millions of people of affordable intercity public transportation and thousands of rural communities of their only link to the outside world." The US Chamber of Commerce argued that the costs of the ADA would be "enormous" and have "a disastrous impact on many small businesses struggling to survive."[35] The National Federation of Independent Businesses, an organization that lobbies for small businesses, called the ADA "a disaster for small business."[36] Pro-business conservative commentators joined in opposition, writing that the Americans with Disabilities Act was "an expensive headache to millions" that would not necessarily improve the lives of people with disabilities.[37]
The Americans with Disabilities Act (ADA) and, if the government entities receive federal funding, the Rehabilitation Act of 1973 generally require that state and local governments provide qualified individuals with disabilities equal access to their programs, services, or activities unless doing so would fundamentally alter the nature of their programs, services, or activities or would impose an undue burden.2 One way to help meet these requirements is to ensure that government websites have accessible features for people with disabilities, using the simple steps described in this document. An agency with an inaccessible website may also meet its legal obligations by providing an alternative accessible way for citizens to use the programs or services, such as a staffed telephone information line. These alternatives, however, are unlikely to provide an equal degree of access in terms of hours of operation and the range of options and programs available.
Additionally, in February 2018, Congress passed the ADA Education and Reform Act, a bill designed to make it harder for disabled Americans to sue businesses for discrimination. Republican lawmakers who wrote and passed the bill argue that the law will help curb “frivolous” lawsuits, while opponents have argued that this law will gut the ADA, essentially giving businesses little reason to follow the ADA guidelines at all.
Shortly before the act was passed, disability rights activists with physical disabilities coalesced in front of the Capitol Building, shed their crutches, wheelchairs, powerchairs and other assistive devices, and immediately proceeded to crawl and pull their bodies up all 100 of the Capitol's front steps, without warning.[38] As the activists did so, many of them chanted "ADA now", and "Vote, Now". Some activists who remained at the bottom of the steps held signs and yelled words of encouragement at the "Capitol Crawlers". Jennifer Keelan, a second grader with cerebral palsy, was videotaped as she pulled herself up the steps, using mostly her hands and arms, saying "I'll take all night if I have to." This direct action is reported to have "inconvenienced" several senators and to have pushed them to approve the act. While there are those who do not attribute much overall importance to this action, the "Capitol Crawl" of 1990 is seen by some present-day disability activists in the United States as a central act for encouraging the ADA into law.[39]
This particular lawsuit amounted to nothing more than a shakedown for cash, as the current laws would make it difficult to win the suit in court (more about this later) but it prompted me to dive deeper into the issue of ADA compliance. Through my research, I discovered there are some new laws on the horizon that could make ADA compliance mandatory, which means web designers and digital marketers need to know how to prepare.

This guy is right on! You should learn new skills that are critical to your success instead of focusing on your business. Just making a website is easy, making one that is easy for your users to navigate, captures your users' interactions, feed that back to a CRM so you can act on it and setting up automation to handle each one properly so you don't lose the customer is not. (And do not forget, the design of your site is critical to the effectiveness of Google and Microsoft Ads. Without them, no one will ever see your new, beautiful site.)
The ADA has been criticized on the grounds that it decreases the employment rate for people with disabilities[48] and raises the cost of doing business for employers, in large part due to the additional legal risks, which employers avoid by quietly avoiding hiring people with disabilities. Some researchers believe that the law has been ineffectual.[49] Between 1991 (after the enactment of the ADA) and 1995, the employment rate of men with disabilities dropped by 7.8% regardless of age, educational level, or type of disability, with the most affected being young, less-educated and mentally disabled men.[50] Despite the many criticisms, a causal link between the ADA and declining disabled employment over much of the 1990s has not been definitively identified.[51]
Being one-third of the way into 2019, we opted to follow up on the 2018 discussion we had regarding ADA Website Compliance. Per last year, making sure your website is ADA compliant is significant in offering an equal opportunity for everyone to experience the products and/or services your business offers. An ADA compliant website also help prevent lawsuits and potential government action.

Predictable: Websites should operate in ways that are familiar and predictable. When a new page element is in focus, the website should not initiate a change of context such as opening a new window or going to a new page. In addition, the website should warn of user-initiated changes of context ahead of time, for instance through the use of a submit button. Navigation and labeling should remain consistent between different pages.

The Department has assembled an official online version of the 2010 Standards to bring together the information in one easy-to-access location.  It provides the scoping and technical requirements for new construction and alterations resulting from the adoption of revised 2010 Standards in the final rules for Title II (28 CFR part 35) and Title III (28 CFR part 36).