Corsearch sells trademark, brand, and content protection. The company dates to 1949. John Mazotis, the CIO, told Techzine how they left a Microsoft 365 estate for Google Workspace plus Slack.
Coen van Eenbergen published the interview on 2 December 2025. This is a journalist write-up of a CIO interview, not a Slack customer page.
The whole Microsoft-to-Google-and-Slack move took three months. Slack itself went in quickly. Google took longer because Corsearch is a pile of acquisitions, some already on Google, some still on Microsoft.
If you are looking at the Teams-to-Slack slice, start with the Microsoft Teams → Slack playbook. John’s interview is the change-management report. The playbook is the export and import path he barely describes.
Why they left
On paper, Microsoft 365 is one platform and Google plus Slack is two. John said the two together had better security, a better user experience, more features, and more integrations than Microsoft 365.
He also said Microsoft 365 was not really one place. People still jumped between disconnected tools. Slack became the hub. Spend approvals and meeting notifications land there. “If I need to approve a spend for someone, I click a button in Slack. I don’t need to go to a different platform.”
He talks to vendors and many customers in Slack now. Email is not the default.
The interview does not give a cost number, a headcount, or a Teams-channel count, so I am not inventing those.
What they moved
John is blunt about the technical work. “Moving a file from Microsoft OneDrive to Google Drive, it works.” That is the file story he told. Most of the budget went to change management, education, and training.
He does not describe exporting Teams chats, importing them into Slack, or copying SharePoint channel files into Slack. Microsoft will export Teams messages through Graph. Slack’s generic CSV importer takes timestamp, channel, username, and text. Meetings, recordings, tabs, and Teams apps do not come along. The playbook already treats those as lost or rebuilt.
Their published story is about how people work after Slack is live, not about a message-for-message import.
They first moved to Slack in February of that year. John does not name the year in the text. The interview ran in December 2025.
Channel fatigue was the surprise
People who had lived in a handful of Teams channels suddenly saw many Slack channels. That wore them out.
Corsearch ran a campaign that said it is fine to leave a channel or mute it. They also tried to keep channels public unless a channel really needed to be private, so search could see the work.
They taught people to make channels for a project, a team, or a job. They added channels for announcements, wins, and new joiners.
John’s line on DMs is the one I would print in a training doc. If you only use Slack as a DM tool, it works, and you are using about 10% of it.
What they gained
Slack plus Google Docs became the daily stack. John said 20 people can edit a Google Doc at once, and you can start a meeting from the doc. He found Microsoft’s co-editing less smooth and less willing to stay in sync.
Huddles cover the quick call. Slack Connect covers the vendor and customer rooms, up to 250 organizations in one channel on paid plans.
He wants Slack to be the morning home screen. Approvals, notifications, and as many internal systems as they can wire in. When they first landed in February, that still felt far off. By the interview he thought they were close, through native integrations and Slack workflows.
Google Workspace also gave them Gemini, NotebookLM, and Studio AI with the suite. Those sit on the executive KPI list. They later launched HR agents trained on policies, handbooks, and local law, as a first-line answer before a ticket. Slack’s thread summaries help people in other time zones catch up.
Those AI pieces are Google and Slack features they turned on after the move. They are not a Teams-import result.
What they skipped or botched
John said they could have handled channel fatigue from day one.
The interview does not list a failed import, a missing private chat, a broken guest, or a rollback. It also does not say they shut Teams down, or how long both tools stayed open.
Teams recordings, transcripts, and apps do not become Slack artifacts. If those still mattered, they are still in Microsoft unless someone archived them. He never says.
Change management did not end at go-live. John now acts as a traffic light for new Slack and Google features. Sales news goes to sales. Finance news goes to finance. He does not dump every changelog on everyone.
What I would copy
Budget the training, not the file copy. John’s team already knew OneDrive-to-Drive would work. The money went to showing people what a channel is for.
Teach mute and leave in week one, before the channel list explodes. Keep new channels public unless you have a reason.
Write down the approvals and alerts that should live in Slack before you cut over. Spend approval was his example. If that still lives in email, Slack is just a louder chat app.
Do not assume Teams history will follow. If you need those threads, export them on purpose and decide what a CSV import is worth. The playbook’s reverse route is Slack → Microsoft Teams.
The Microsoft Teams → Slack playbook is the checklist I would run. Use the Techzine interview for the “pay for change management” call.