Weak revenue guidance spoiled a big step to profitability.Shares of Appian (APPN -11.73%), a cloud software focused on business process automation, were falling today, even as the company beat estimates in its second-quarter earnings report. It pulled forward guidance to reach break-even on an adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA) basis.Despite that, investors seemed underwhelmed by weaker-than-expected revenue guidance for the third quarter and full year.As a res ...