I've had a similar experience with tax preparers. I once decided to hire two different tax preparers, both of whom had good reviews and strong credentials. I na

I've had a similar experience with tax preparers. I once decided to hire two different tax preparers, both of whom had good reviews and strong credentials. I naively assumed that I would spend an hour tops comparing the two returns side-by-side, and examining any small differences between them. What ended up happening was that both returns were so dramatically different, along many different dimensions. It took me nearly 40 hours to catalog all the different decisions made by each preparer, and which of the two decisions is the better one. Through this exercise, I realized that both preparers had made some major errors - and by reconciling them, I ended up saving more than $10,000, while also making my tax returns more resilient if audited. I'm convinced that for any non-trivial decision in any field, the best way to make them is to hire multiple independent professionals, and cross-check their independent recommendations. And yes, this applies to software engineers as well.