As earnings season continues, many growth stocks will get the spotlight this week. Investors will likely be watching updates closely as they come at an interesting time: Companies are up against year-ago comparisons that were heavily affected by consumers sheltering at home amid the COVID-19 pandemic.

Two growth stocks reporting results this week that will likely provide particularly telling insights about their post-COVID-19 performance are Fastly (NYSE:FSLY) and Roku (NASDAQ:ROKU). Both companies are up against some tough comparisons as far as their platform usage goes.

Both are reporting their third-quarter earnings after market close on Wednesday, and investors will likely be watching the releases closely. Here's a preview of some of the key items to keep an eye out for when their earnings releases go live.

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Fastly

Edge computing specialist Fastly benefited from a surge of internet usage during the pandemic. Given its usage-based business model which makes more money as usage increases, this helped revenue soar. Revenue in the company's second and third quarter of 2020 rose 62% and 42% year over year, respectively.

But growth has slowed since then, though this slowdown has been for more reasons than tough year-ago comparisons. Fastly lost a major customer in late 2020. Furthermore, the company suffered a brief platform outage in Q2 of this year that ultimately led some customers to reduce their reliance on the platform.

For Q3, investors are expecting Fastly's revenue growth to accelerate a bit from the 14% growth it reported in Q2 2021. But growth is still expected to be well below 2020 levels. Management guided for third-quarter revenue to be between $82 million and $85 million. The midpoint of this guidance range translates to a year-over-year growth rate of about 18%.

Roku

While investors will undoubtedly be watching Roku's third-quarter revenue growth, the more closely followed metric may be its streaming hours. The key metric fell sequentially in Q2 2021, declining from 18.3 billion hours to 17.3 billion hours.

But the streaming-TV platform company's management team shrugged it off, noting in its second-quarter shareholder letter that customers simply "sought increased out-of-home entertainment activities (such as dining and travel) in Q2 as a result of pent-up demand and the loosening of COVID-19 restrictions." Furthermore, management was quick to point out that Roku streaming hours increased 19% globally year over year.

Investors should look to see if Roku's third-quarter streaming hours returned to sequential growth in Q3.

As far as Roku's revenue growth goes, the company guided for third-quarter revenue to be between $675 million and $685 million. The midpoint of this guidance range implies 50% year-over-year growth.

Fastly and Roku will both report their third-quarter results after market close on Nov. 3.

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