A day after Microsoft execs announced plans to lay off 18,000 employees , tidbits about what's happening behind the scenes continue to trickle in.

The largest number of people cut are former employees of Nokia who joined Microsoft as part of the company's acquisition of its handset business. But, as I blogged yesterday, a number of other teams and business groups are being hit by the cuts , as well.

The unified Operating Systems Group (OSG), under Terry Myerson, is cutting a substantial number of testers , as well as the Xbox Entertainment Studios team , charged with creating original TV content for Xbox. I've heard rumors some in Windows marketing are being cut, too.

Here's the memo Myerson e-mailed to the OSG team on July 17 announcing the refocusing of the team:

Re: Focusing our team

Team, As Satya shared last week, and we’ve been discussing for almost a year, we are making broad changes in how we engineer products. Thus, today we are restructuring some parts of our team in three areas: consolidating some of our geographically distributed teams, cancelling some projects to increase investment on higher priorities, and changing the ratio of people working across disciplines as part of our new engineering process. For individuals in Redmond whose jobs are impacted, a leader within their organization will have reached out by 11:30 AM PDT today; timing outside of Redmond will vary. This change is so incredibly hard. People whose jobs are impacted by these changes are our colleagues and friends. The company is offering support, services and assistance during this transition in a number of ways. For those of you whose jobs are impacted by this, I want to thank you for your contribution to Microsoft and our customers, and wish you the best. It will take time for all of us to adjust to today's announcement, but we can now move forward knowing that we have completed the OSG-wide restructuring in the US today; the process outside the US will be completed according to local law and practices. -Terry

The reference to the cancelled projects is partly in reference to Xbox Entertainment Studios, I hear from one of my sources. There are likely other cancelled projects, too, but I don't have information (so far) on what these are.

The organizational changes Myerson mentions as being completed in the U.S. yesterday are focused largely around decreasing the number of testers as compared to the number of developers, resulting in layoffs of a number of those testers. This "combined engineering" plan, meant to undo the functional management structure that has been in place at Microsoft for the past few years, is new to OSG, but not new to other parts of Microsoft, including the Applications and Systems Group and the Cloud and Enterprise Group.

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The changes around test were not completely sudden, I hear. A few months ago, Microsoft changed the job of the OSG test organization, renaming it "Quality," and refocusing the team from writing tests to "measuring quality." That meant the job of writing tests was already moved to the dev team, leaving many of those in the Quality team with less to do -- and clearing the way for the tester cuts.

The other group in OSG that seemingly was hit by some unknown number of cuts were "individual contributors," not product managers, I hear. There also may have been cuts of some in the OSG build team, resulting from redundancies created by the merging of the Xbox operating system, Windows Phone operating system and Windows operating system build teams, some are claiming.

Under CEO Satya Nadella -- who is very focused on "data and applied science" -- new internal development and testing tools are coming. At the same time, there are a number of Microsoft employees who have been working on fleshing out data science teams inside their respective organizations since last year. (I hear Dean Hachamovitch is no longer the Chief Data Scientist for the company, all-up, however; I am not sure who is.)

Of course, how these new processes and tools will affect Microsoft's Windows, Windows Phone and Xbox code and rollout schedules remains to be seen.