The definition of autism has changed to pull in masses more people over the years, so if you're an older software engineer you may be autistic using the up-to-date definition.
With the DSM-5 and it's removal of Asperger's as a separate diagnosis the diagnosis criteria has been made stricter. People that would have formerly been diagnosed as Asperger could theoretically not be anymore under ASD.
The percentage of people with autism in a population is very stable and we know there is a huge genetic component to it.
People are getting diagnosed more but the amount of people with autism has likely stayed stable.
Which is really, really good thing. A diagnosis is live changing. The earlier you get diagnosed and the more supportive your network is, the better the outcome.
