In 2009, when Yahoo! was flailing in its tail-spin of epic proportions, Carol Bartz was brought onboard as the new CEO to save the sinking ship. Her Baptism of Fire ended in 2011 with a less-than-glorious conclusion (think: an unceremonious telephonic firing followed by expletive-filled tirade interviews with Fortune magazine).
Drawing on Biblical imagery, the term refers to a trying or challenging circumstance that an individual or firm experiences, which will end in either failure or success. Other common examples could include a takeover attempt from a competing organization (when AOL acquired Time Warner in 2000, which promptly lost $200 billion in less than two years as a result of the dotcom boom), or a risky initial public offering (Uber's plans for 2019).