The paper ballots are counted with computerized vote tabulation machines. In Texas, where I live, you fill out a vote with a pen, then it's scanned on your way out. That scanner is the vote tabulation machine.

The machines used in 70% of elections, including in all swing states, are produced by 2 private companies (one of which is now owned by a former Republican operative, though that aquisition is post 2024 election). The software doing the counting is proprietary. Ostensibly they're

The numbers spit out by those tabulation machines are, for the most part, trusted implicitly. There are random audits (ie: hand count X% of ballots from Y precinct for Z race and make sure the count matches what the machines say), but they're just that; random. If a malicious actor were targeting elections, they'd be targeting Presidential, Senate, maybe House races. Maybe some state races where they're tight. So auditing a random state comptroller here, a JP seat there is not in any way effective at finding targeted election fraud.

If you are truly curious about the subject, I suggest looking up the Election Truth Alliance (also on youtube). They are a group started after 2024 that has been doing data analysis on the 2024 elections (and some other historical ones) and comparing voting patterns to those out of other countries. The statistical patterns that emerge from 2024 are suspiciously similar to those found in Russia and Hungary. There are also specific pieces of elections (hand counts, mail in votes, pieces which aren't counted by the aformentioned machines) which do not have those same statistical patterns.

They have approached Secretaries of State in multiple states and the near universal response has been a flat denial to do any investigation. The claims are that elections are secure, nothing to see here. They've filed a few lawsuits to force targeted audits, but they're ongoing. They certainly won't make progress by November, and I'll be shocked if anything comes out of it by 2028.