First off, disinformation occurs around every election and has for decades, long before voting machines were ever introduced, so you can't take any claim made at face value.
For someone who is a computer programmer by profession - wherein attention to detail and logical thinking are prerequisites to doing the job - I'm rather surprised you are not applying those very same skills in your evaluation of the facts pertaining to both Trump and the election.
One cannot ignore the fact that as early as 2016, Trump was alredy claiming the elections were rigged when Ted Cruz won Iowa and later than year claiming that if he didn't win the Presidency, it was because of massive voter fraud. Even after he won due solely to the electoral college, he proclaimed he'd won the popular vote too (which he actually lost by almost 3M votes) and then went on to state how attendance at his inauguration was the largest in history (another BS story). The man is a pathological liar and malignant narcissist who is incapable of admitting any defeat. His lies have been so prevalent that the Washington Post began documenting them into a searchable database beginning January 20, 2017. As of October 16, 2020, there are 25,653 listed. Don't take my word for it though, go look for yourself.
With respect to the voting machines, there are a number of false claims made about them by Guiliani, Powell, and others, starting with who owns them, where they were developed, etc. Dominion - the machines used in the swing states plus 20 or so others - was founded 18 years ago in Toronto, Canada, by two Canadians who sold it to a US equity firm in 2018. Hugo Chavez (who died in 2013), Venezuela,and every other ludicrious claim made by Trump allies have never had any part in the development nor ownership of those machines.
Each of those machines produce a paper ballot receipt when a selection is made so that users can verify their choice was accurately recorded, which they then confirm or deny on the machine. Once confirmed a pdf copy of that ballot is produced and retained to act as a paper trail for future audits. Those paper ballots were what was used during the hand recounts in Georgia and Wisconsin to valid the results of the first count. It should also be mentioned that those machines are all air gapped and were never connected to the internet (where they could possibly be hacked).
To be continued....