Microsoft Build 2025: The Rise of the Agentic Web and Other Key Takeaways

At Microsoft Build 2025, Satya Nadella took the stage with a message that was both reflective and visionary. In a keynote that bordered between developer passion and strategic ambition, Nadella made it clear: we’re not just witnessing the next wave of software evolution, we’re building it. And it’s called the "agentic web."

Building in the Middle Innings

"We're in the middle innings of a platform shift," Nadella said, setting the tone early. He drew parallels to pivotal tech moments, like Windows in ’91, the web stack in ’96, and cloud-mobile in 2008. Now, in 2025, it’s all about building out an open, scalable, agentic web.

This new web isn't about single-purpose apps but platforms of interconnected agents that can reason, act, and collaborate. The shift is from vertical, monolithic stacks to a mesh of AI-powered agents that can be woven together, democratizing access to computing and creativity.

How Microsoft is Empowering Developers at Scale

Nadella's keynote radiated excitement about developer tools. Visual Studio, which  now serves over 50 million users. And, GitHub? A staggering 150 million. GitHub Copilot alone boasts of 15 million users.

Being relevant to the perpetually evolving tech landscape is also the key. "We're taking Copilot from being a pair programmer to a peer programmer," Nadella said. Now, developers can assign tasks to Copilot.  It doesn’t just suggest code, it executes, reviews, and creates pull requests autonomously.

In a on stage demo, Nadella showcased assigning an issue directly to Copilot. The AI agent picked it up, created a new branch, started GitHub Actions, and even drafted a pull request. It’s the kind of functionality that blurs the line between assistant and teammate.

From Code to Reliability: What Autonomous Agents can do?

The keynote unpacked some interesting initiatives. It introduced autonomous agents built into GitHub for SRE (site reliability engineering). Imagine getting paged at 2 AM for a production issue. Now, an SRE agent can triage, mitigate, and log the incident—then assign follow-ups to Copilot.

This is a new level of developer empowerment. These agents work securely within branches, respect CI/CD governance, and can even collaborate with other agents in the ecosystem. Nadella emphasized, "We're opening this ecosystem to you, all of you will build these agents."

Conversation with Sam Altman: Agents as Teammates

Joining Build remotely, OpenAI CEO Sam Altman reflected on the evolution of AI and software engineering. "It's wild to me that the agentic coding experience is finally here," he said. Altman in a way framed it as true task delegation: agents that can reason, act, and operate in parallel across complex workflows. This is one big takeaway.

He also gave a peek into evolving advancements in OpenAI’s model roadmap. Like, for instance, fewer decisions for users, more automation, better reliability, and seamless tool use. "Models will just do the right thing," Altman observed. In a way it summed  up the direction of next-gen AI experiences.

The UI for AI and Microsoft 365 Copilot

At the fulcrum, and pivoting this agentic wave lies in Microsoft 365 Copilot, now generally available. Nadella called it the biggest update since Teams' launch. It merges Chat, Search, Notebooks, Create, and Agents into a single intuitive interface- "the UI for AI," as he described it.

Notebooks let you curate heterogeneous data: pages, emails, files into one workspace. While the researcher and analyst agents synthesize information and generate forecasts. These are not just productivity features; they’re AI companions embedded in daily workflows.

What seals the deal? These agents are multiplayer. With Teams AI library and one line of code, developers can now build and publish agents that work across Microsoft 365 and Teams, all accessible to hundreds of millions of users.

Tailormade Intelligence with Copilot Tuning

In a move that democratizes model customization, Microsoft introduced Copilot Tuning. Enterprises can now fine-tune models on their data, tone, and workflows. A legal firm could train Copilot to reference past arguments. A consulting firm can create vertical-specific reasoning tools. It’s AI, tailored by and for you.

What is the App Server for the Agentic Age: Welcome to Foundry

As agents scale, Microsoft needs infrastructure to support them. Enter Azure AI Foundry, its a full-stack platform to build, manage, and orchestrate AI-powered agents.

Nadella likened it to an "app server for the AI age." Foundry offers model selection, orchestration, evaluation, and multi-agent frameworks. It now supports Grok (xAI), Mistral, LLaMA, and thousands more via Hugging Face.

In a standout use case, Stanford Medicine used Foundry to orchestrate tumor board meetings, aggregating radiology, clinical notes, PubMed research, and trial data. This led to amazing results.  AI-assisted care that’s faster, better, and equitable across institutions.

The Trio: Copilot, Foundry and Windows Make the Full Stack

Interestingly, Microsoft is closing the loop between its products. Foundry models can now be dropped into Copilot Studio. Agents can be pushed to Microsoft 365. And with Windows AI Foundry and Foundry Local, developers can run agents natively across devices.

Windows now includes native support for MCP (Model Context Protocol), with agent identity and policy enforcement via Entra ID. GitHub Copilot Agent Mode works seamlessly with Figma, WSL, and other MCP-compatible apps.

Grok Joins the Fray

In a pre-recorded chat, Elon Musk shared his vision for Grok 3.5, a model that reasons from first principles using the tools of physics. Grok aims for truth with minimal error, a key for AI safety, Musk stressed. "Honesty is the best policy," he said, "especially for AI."

Grok joins Azure’s ecosystem, adding more diversity to the AI mix. Developers can now mix and match across a unified provisioning model.

Developer-Centric and Open by Design

Throughout the keynote, Nadella returned to one theme: developers are at the center of this shift. Whether it’s building agents, tuning Copilot, or orchestrating apps with Foundry, the tools are there—and the platform is open.

"Each platform shift needs its app server," he said. "We’re building it now for the agentic web."

From infrastructure to IDEs, from OpenAI to open source, Build 2025 was less about what Microsoft is doing and more about what developers can now do. And that, perhaps, is the ultimate promise of the agentic era: intelligent tools that empower every creator, coder, and company to move faster, with greater purpose, and on their own terms.