What toolsets, technologies and workflow would you apply here and how?
Voters are not registered to or by any political party. Can vote for whoever they please.
Voting is done by 'good old-fashioned' paper and pencil. Votes are counted by electoral commission staff, and scrutineered by members of the relevant political parties. Those paper votes should all be able to be counted within a few days. They are a self-evident paper-trail, easily able to be recounted and double-checked. Machines are to be banned, as they can fiddle the books very easily.
Voting is allowed to be done over several weeks, meaning that everybody who wants to has a chance to get to a ballot-box. Voting absentee (voting at a location not within your normal voting area) is handled by the electoral commission staff. Mail-in voting is handled likewise.
Political party members are not permitted within the actual voting area. Only voters and electoral commission staff allowed in there. Steps are taken to prevent too many voters in the area at the one time.
Voting sites are sufficient in numbers that waiting times are very short, less than an hour.
This election was different from the expectations of many on both sides. You are observing people trying to come to terms with how expectations could have differed so much from the apparent reality. The accusations of fraud are just one such explanation.