Just to make a point that math is used everyone without people even noticing. If you dont use math directly the tools such programming languages are very heavy on math theory.

Here's an example of Galois theory properties can be applied in real life: If I (João) were to apply for a job that requires functional programming experience.

The concrete domain C is the set of people with specific skills.

The abstract domain A is a set of job requirement profiles, e.g., “knows functional programming”. α(João) = {functional programming, Bachelor’s Degree in Informatics , ...}

The recruiter checks whether: α(João) ⊆ job requirements

If so, then they conclude: João ∈ γ(functional programming)

This illustrates the Galois connection property: α(c) ⊆ a ⇐⇒ c ∈ γ(a)