Regardless of the outcome, the sheer magnitude of what Mr. Yang has achieved seems to be dawning fully upon him. He broke down in tears last week at an event in Iowa as he observed that campaigning for the last two years had been “the journey of my life.” And speaking with voters in New Hampshire on Wednesday, he shared what he said he had been telling his two young boys in recent days: “Daddy’s got a big deadline on Tuesday.”

When the Democrats do eventually pick a nominee and reflect on this process, the rise and staying power of Mr. Yang in this race — outlasting some governors and senators, drawing money and interest far longer than most people expected him to — will offer a clear lesson: In a campaign of maximum anxiety and maximum field size, an outsider with a specific message and a fanciful promise of free money can stand out.

But what was lost in the novelty, his former employees say, was real scrutiny.

Some of his former employees see, in Mr. Yang’s unlikely staying power into the early 2020 nominating contests, not just an odd embrace of an outsider, but a casual disregard for allegations about how he treated women who worked for him. It is a collective shrug, they say, that they find all the more disconcerting given how explosive and relevant gender has become in the race.

At the same time, Mr. Yang’s cavalier use of racial stereotypes about Asian-Americans and what his former employees say is a surprising lack of attention to his record as a chief executive have also gnawed at those who say they watched their boss similarly fumble delicate topics and conversations for years.

Some of Mr. Yang’s former employees describe a jubilant, funny, thoughtful leader who gave high fives and fist pounds, and sought to keep the mood light — a man who resembles the candidate they see on the campaign trail. Mr. Yang does not drink alcohol, but he would buy the first round during company celebrations, they said. He took employees on ski trips and to sporting events. And he encouraged people to do well while holding them to account.

But even years after their time spent working for him, many other former employees still recall specific episodes that they say highlighted Mr. Yang’s shortcomings: several women allege that he treated them unfairly when it came to compensation and employment; he once offhandedly remarked that the nonprofit fellowship program, Venture for America, might simply not be the best fit for black applicants; he convinced his nonprofit to pay for his family to join him on a lengthy fund-raising trip to California that proved largely unsuccessful.