When you want to build any digital service or product, you maybe just need to keep some requirements in mind, without being overwhelmed with so many technicall stuff about a11y.

Mini A11y checklist

• Provide text alternatives for any non-text content, example: an icon button needs a my favorites

• All functionnality is keyboard accessible without keyboard traps (provide a visible focus on all interactive elements, the order must stay logical, no traps)

• provide enough time to read and use content (or a stop/pause button on animations)

• forms include labels or instructions (for visually impaired users and cognitive disabilities)

• text and background must use good color contrast (https://monsido.com/tools/contrast-checker)

• user can resize text without breaking layout (like overlapping texts)

How to use it

These rules are coming from the WCAG 2.1 criterias, level A and AA.
You should use this list before starting the development.

Generally speaking, it might be longer to provide an accessible product when you think about accessibility after the development stage...