AutoGen is Microsoft's multi-agent AI framework. If you tried v0.2, you hit the same bullshit everyone else did: agents hanging forever, memory leaks that would eat your entire server, and debugging async agent coordination was like debugging quantum physics with a fucking magnifying glass. The v0.4 rewrite wasn't an upgrade - it was Microsoft admitting the original architecture was fundamentally fucked.
Why v0.4 Actually Works (Unlike the v0.2 Disaster)
Version 0.4 fixes the disasters that made v0.2 unusable at scale. v0.2's memory leaks were insane - I saw agents eating like 10+ gigs of RAM doing basic CSV parsing, took down our dev environment a couple times before I realized what was happening. The original architecture just fell apart with more than 3-4 agents - infinite conversation loops, agents talking past each other, everything would hang. Microsoft finally admitted this in their blog post, though they used polite terms like "scalability constraints."
The new architecture has three layers (because of course it does):
Core Layer: Event-driven messaging that supposedly prevents the endless loops of v0.2. Agents can now operate asynchronously without blocking the entire system when one agent decides to go rogue or a network call times out.
AgentChat Layer: The "compatibility layer" that's supposed to make migration from v0.2 easy. Spoiler alert: you'll still need to refactor half your code. The streaming messages are nice when they work, but expect to spend time debugging the observability features.
Extensions Layer: Where all the third-party integrations live. The Docker code executor actually works now (unlike v0.2 where it would randomly eat all your RAM), and the MCP integration is useful if you can get it configured properly.
The "Enterprise-Ready" Marketing vs Reality
OK, enough theory. What does this mean for production? v0.4 is way better than v0.2, which isn't saying much since v0.2 was basically unusable. The OpenTelemetry integration is actually useful for debugging agent interactions - you'll need it when trying to figure out why your agents are stuck in a loop again. The type support helps catch errors at build time instead of discovering them when your agent system crashes in production.
Cross-language support sounds impressive until you realize it's just Python and .NET. If you're running a polyglot shop, you're still writing wrapper APIs. The .NET support works fine if you're already in the Microsoft ecosystem, but don't expect seamless interoperability.
The modular architecture is genuinely useful. You can swap out model clients without rebuilding everything, and the custom memory systems actually work (unlike v0.2 where custom memory was broken more often than not). Just don't expect the documentation to cover all the edge cases - you'll be reading source code at 2am wondering why your agents won't fucking cooperate and why the pluggable components hate each other.
That's the theory anyway. Let's talk about what happens when you try to run this in production...