Euna Solutions builds finance software for the public sector. It had Slack for chat and a growing Microsoft 365 estate for everything else. The two did not fit.
BITSUMMIT published the write-up as a 2024 success story. This is a vendor case study. The numbers below are BITSUMMIT’s.
If you are looking at the same route, start with the Slack → Microsoft Teams playbook. Microsoft’s Slack to Teams Migration Tool is the first-party path. BITSUMMIT used Slack’s Enterprise Export, its own scripts, and Microsoft Graph.
Why they moved
Slack sat next to Outlook, SharePoint, and the rest of Microsoft 365. People switched tools to do work that already lived in Microsoft. BITSUMMIT says that created friction between departments.
They wanted one place inside Microsoft 365. The risk was losing years of Slack history, files, and channel structure, while more than 500 people kept working.
The page does not name a Slack bill or a Microsoft 365 license change, so I am not quoting a saving.
What they inventoried
BITSUMMIT mapped the Slack workspace before it touched data.
The count they published is more than 200 channels, with roles and permissions, plus about 1 TB of messages, files, and integrations, and more than 50 third-party apps and custom integrations.
That inventory is the useful part of the story. You cannot pick a migration tool until you know which channels are public, which are private, and which apps still fire.
Slack’s export options change by plan. Public channels export on every plan, as JSON plus file links. Private channels and DMs need Business+ or Enterprise, plus an application. Slack’s import and export guide is also clear that those full exports exist for legal and compliance use, not as a casual dump.
BITSUMMIT says it pulled complete data sets with Slack’s Enterprise Export. It does not publish the Slack plan, and it does not say whether DMs were in that export.
How they moved it
They picked tooling for a large transfer, staged the work so the business stayed up, and ran a communication plan across the company.
The data path they name is Slack Enterprise Export, then purpose-built scripts, then Microsoft Graph and supporting tools. They say channel structures and permissions survived.
They configured Teams to match Euna’s org chart. Azure AD single sign-on (now Microsoft Entra ID) covered login. They rewired the third-party apps they still needed.
Adoption was its own project. Fifteen interactive training sessions and custom user guides. A pilot group before the wide rollout. Support channels inside Teams once people switched.
Microsoft’s own tool is close to that export-then-import shape. You upload the Slack zip to Azure Blob Storage, scan it, map users and channels, then import. It moves public and private channels, threaded messages, standard reactions, file attachments, membership, and canvases or lists as HTML and JSON files. It does not delete anything in Slack.
Microsoft also says, in the planning guide, that Teams does not import direct messages. Slack Connect channels are unsupported. Archived channels stay behind unless you unarchive them before export. Apps and workflows do not become working Teams apps.
BITSUMMIT’s page never mentions DMs, Slack Connect, or archived channels. “Zero data loss” is their headline. I am leaving Microsoft’s documented gaps next to that claim.
What they say they gained
Within two weeks of cutover, 95% of Euna’s people were actively using Teams. That is BITSUMMIT’s adoption number.
They also published a 40% lift in communication-tool satisfaction from employee surveys, 30% less tool switching, 25% more collaborative document editing through Microsoft 365, and 20% less IT overhead from centralizing management.
I have not found Euna’s own engineering post with those figures. Treat them as the implementer’s scorecard.
The duration on the page is two weeks, delivered in 2024, under a managed-services engagement.
What the vendor page skips
It does not list a failed channel, a renamed file, an unmapped guest, or a rollback.
It does not say what happened to Slack DMs. Microsoft’s first-party tool will not take them. A partner script talking to Graph might, and BITSUMMIT does not say it did.
It does not name which of the 50-plus apps they rebuilt, and which they retired. The playbook treats every Slack workflow as lost until you replace it.
It does not say when Slack was frozen or turned off.
Incremental imports have a known hole in Microsoft’s tool. New replies to a thread you already moved do not come across. BITSUMMIT says the plan was phased and the business stayed up. It does not say how they handled live threads during that window.
What I would copy
Inventory channels, permissions, file volume, and apps before you pick a tool. BITSUMMIT’s 200 / 1 TB / 50+ list is the right shape, even if your numbers are smaller.
Decide DMs, Slack Connect, and archived channels in writing. If Microsoft’s tool is the path, those are lost unless you archive them elsewhere. If a partner says “zero data loss,” ask which of those three they mean.
Run a pilot group, then train before the wide cutover. Fifteen sessions is their number. The useful idea is training plus a Teams support channel on day one, not a Friday email.
Reconcile channel counts, file hashes, and membership after each wave. Microsoft’s tool will scan the export and let you pick channels and a date range. Use that. Do not trust a vendor homepage for the totals.
The Slack → Microsoft Teams playbook is the checklist I would run. Use the BITSUMMIT page for the inventory-and-training shape, and remember it is a vendor case study.