Microsoft Teams is the collaboration platform that combines chat, video meetings, file sharing, and application integration into a single workspace, and for companies already running on Microsoft 365, it's deeply embedded into their daily operations. From a custom development perspective, Teams matters because many enterprise clients live inside it all day. When I build custom web applications for businesses that run on the Microsoft stack, Teams integration is frequently part of the conversation. That means sending notifications to Teams channels via incoming webhooks, building Teams tabs that embed custom dashboards or tools directly inside the Teams interface, or creating bots that let employees interact with custom systems through conversational commands. The Microsoft Graph API makes it possible to read and write to Teams channels, manage team memberships, and trigger workflows programmatically.
Microsoft Teams launched in March 2017 as Microsoft's response to Slack, which was rapidly eating into enterprise communication. But the backstory goes deeper. In 2016, there were internal discussions at Microsoft about potentially acquiring Slack for $8 billion. Bill Gates reportedly argued against the acquisition, suggesting Microsoft should build its own competitor instead. CEO Satya Nadella agreed, and the Teams project was greenlit. Microsoft had a massive structural advantage: it could bundle Teams for free with Microsoft 365 subscriptions that hundreds of millions of users already paid for. This bundling strategy worked, Teams went from zero to 270 million monthly active users by 2022, far surpassing Slack's user count. The COVID-19 pandemic accelerated this growth dramatically, with Teams becoming the default video call platform for schools, hospitals, and government agencies worldwide.
The decision to not acquire Slack and build Teams instead is considered one of the most consequential strategic calls in modern Microsoft history. When Salesforce later bought Slack for $27.7 billion, many analysts pointed out that Microsoft essentially built a more widely adopted competitor for a fraction of that cost. But here's a lesser-known detail: Microsoft Teams was actually built on the foundation of Skype for Business, which itself was a rebrand of Microsoft Lync, which was a rebrand of Office Communications Server. The product went through three identity changes before becoming Teams. Also, the European Commission launched an antitrust investigation into Microsoft's bundling of Teams with Office 365, which led Microsoft to begin offering Teams as a separate product in Europe in 2023.
