But results in some more vital areas were a bit less impressive. Azure, Microsoft’s public cloud service that is second only to

Amazon’s

in size, saw revenue grow 35% year over year. That was two percentage points below analysts’ forecasts and a big slowdown from the 46% growth averaged over the past four quarters. The strong dollar had a big impact—Microsoft says growth would have been 42% otherwise. But that still marks a notable deceleration from currency-adjusted growth rates of the past four quarters. The company also projected a further five-percentage-point decline for Azure growth in the December quarter, noting that some “moderation” in use of the service is expected to continue.

Azure’s outlook fed into what was a disappointing forecast overall for the current quarter, and that wasn’t what tech investors wanted to hear—especially following a disappointing report from Google-parent

Alphabet

the same afternoon. Microsoft has never been thought to be immune to recessionary forces, but its exposure to a wide array of businesses that include software, tech hardware and even advertising give it more diversity than its big tech peers, which have a stronger reliance on individual sectors. Microsoft has also minded its bottom line well; operating margins of 41.7% for the past four quarters well exceed the 30.5% average of

Apple

and the parent companies of Google and

Facebook

for their most recent trailing 12-month periods.

But the bulk of Microsoft’s success has come primarily from becoming indispensable to the world’s businesses that need everything from cloud computing to Excel spreadsheets to advertising and recruiting services on LinkedIn. That also means Microsoft is typically the last to fall under the knife: A recent survey of CIOs by Jefferies found that 67% expect to increase their spending with Microsoft next year.

A weakening Microsoft is thus a bad sign for tech all around. The company’s stock slid 7% Wednesday morning, setting up for what could be its worst post-earnings drop in at least five years, according to FactSet. The Nasdaq Composite fell more than 1%, while Amazon—Microsoft’s archrival in the cloud-computing field—saw its shares fall more than 4%.

“We see this as a generally weak macro environment having a material effect on a broad-based, well-run company,” John DiFucci of Guggenheim wrote in his note on Microsoft. Alex Zukin of Wolfe Research was even more succinct: “Winter is here, it’s coming for everyone and no software vendor will be left unscathed.”

Write to Dan Gallagher at dan.gallagher@wsj.com