Ask any software architect what they do, and you’ll get a mix of diagrams, references to patterns, and probably a whiteboard full of arrows. For the last several years, the architecture stack has been surprisingly stable. Databases, messaging systems, identity providers, application frameworks, these core layers have matured, standardized, and found their place in most systems. Architecture has largely been about making smart decisions within that established structure: choosing components, defining boundaries, and setting the blueprint for how everything fits together and scales.
But something fundamental is shifting. The past few years have seen the rise of Large Language Models (LLMs) and AI-native applications that no longer just fit into our architecture. This shift isn’t about adding AI to the stack. It’s about the stack evolving in response to AI. And that has serious implications for how we design, scale, and reason about modern systems.
As someone who’s spent a career bridging enterprise architecture and machine intelligence, I’ve watched this transition up close. And like any good shift, it's coming with new patterns, new abstractions, and no shortage of questions.
In this post, I want to start exploring some architecture patterns that are starting to emerge in this AI-native world. These are patterns we’ve encountered first-hand at Catio as we build real systems that use AI, not as a sidekick, but as a core layer.
Let’s start with where it all began: foundation patterns.
Architecture patterns have been around forever. They’re how we’ve dealt with complexity by naming common solutions to common problems. From layered architectures to message queues, we’ve relied on patterns to keep systems understandable and, ideally, maintainable.
Back in the day, when Java ruled the earth and XML was somehow acceptable (I’m not saying I had a hand in that state of affairs, just don’t do a search, trust me) the Gang of Four design patterns took this even further. Observer, Factory, Strategy, all the greatest hits were there. Whether or not you remember them by name, if you’ve built any non-trivial system, you’ve used them. They gave us a shared language for talking about structure and responsibility without reinventing the wheel every time.
The power of these patterns wasn’t just in the solutions they provided. It was in the shared mental models they enabled. Two architects could look at a system diagram, nod knowingly, and say “Ah, classic decorator pattern,” before moving on to argue about versioning strategy.
But while the classics still matter, the systems we’re building today are changing. AI is introducing a different class of functionality. And like every meaningful shift before it, it’s starting to shape how we design systems, because AI is no longer something you “integrate” but something you architect with and around.
Every so often, a new capability comes along that earns a permanent spot in the architecture toolbox. Message queues gave us decoupling and reliability. Columnar databases gave us fast analytics at scale. Containers reshaped how we deploy and manage software. These weren’t trends, they were step changes. They didn’t just get integrated into the stack, they changed what the stack was.
Modern AI, and specifically large foundation models, is the latest shift of that kind. We now have systems that can reason across unstructured data, summarize complex behavior, generate code, translate across domains, and interact with humans in natural language. These aren’t narrow use cases. They’re general-purpose capabilities that unlock entirely new patterns of interaction and automation.
That means they need to be treated as architectural primitives. You can’t bolt on AI as a feature and expect it to behave like the rest of the system. It changes the control flow. It changes how users interact. It changes how you route, store, and retrieve context. And like the capabilities that came before it, it creates ripple effects, forcing new abstractions, new interfaces, and new design patterns. That’s the shift.
In traditional enterprise architecture, the foundational layers of a system have remained largely stable for decades. You have your compute layer, your storage layer, your messaging and orchestration, maybe some identity sprinkled in for security. When a new tool came along, it was usually another service or database to slot into one of these layers.
AI breaks this model. It doesn’t just live on top of your stack, it seeps into the middle of it. Increasingly, AI is not something you call out to for the occasional classification or summarization. It’s a layer in its own right.
Specifically, Large Language Models are being woven into systems the way databases and message queues once were. And just like those earlier innovations, they are forcing new design choices:
This shift creates the need for new abstractions. You can't wrap an LLM call in a simple API gateway and call it done (well, you could, last year, but those days are over). You need prompt routers. Memory layers. Guardrails. Feedback evaluators. All of these form a supporting cast around the LLM that make it behave slightly more like a traditional system component.
We are now seeing stacks evolve where the question is no longer "Where do we add AI?" but "Which layer of our system is the AI?"
We’re now seeing a set of architectural patterns take shape around AI. Some are extensions of existing practices. Others are entirely new. All of them are attempts to integrate AI as a proper part of the stack.
Here are a few that stand out (I’m still trying to figure out some cool names for them. Open to suggestions. Winner gets something, I don’t know yet 😊).
In this pattern, the LLM acts as the front door to your system. Instead of structured UI inputs or rigid API calls, users interact through natural language. The model maps that intent to something the system can actually execute.
You’ve seen this in:
The key here is translation. The model doesn’t own the business logic, it just figures out what the user is trying to do. Think of it as a semantic adapter between humans and machines.
Rather than decomposing logic into services, we’re starting to decompose it into agents—autonomous components that can reason, act, and communicate.
This shows up in:
It’s a shift in mindset. You’re not orchestrating APIs, but instead you’re coordinating actors with intent.
In this pattern, the model isn’t just taking input, it’s driving the flow. Instead of hardcoded pipelines, the LLM determines what steps to take, which tools to use, and when to stop. It becomes the logic engine behind:
The upside is flexibility. The downside is debugging workflows written by something that doesn’t log its reasoning (but even this can be mitigated, by logging agent conversations for example, as we did)
MCP is an open standard for connecting models to external tools, APIs, and data sources. Instead of hardcoding tool logic or prompt scaffolding, models can discover and invoke capabilities at runtime using a structured, JSON-RPC interface.
The model acts as a client. Tools expose themselves as servers—advertising what they can do, what resources they offer, and how they should be used.
This lets you:
We’ve started adopting this pattern at Catio to make our agent architecture more modular and transparent. It’s early, but it’s already paying off.
Traditional systems handle feedback through monitoring, logging, and postmortems. AI-native systems need feedback in the loop.
We’re now seeing:
It’s not just about improving the model, but about improving the system around the model. That system needs to be architected to support learning, not just execution.
These patterns are starting to stabilize. Not because we all agreed on them, but because they’re working. They solve real problems, at scale, under load.
AI is no longer a point solution. It's a capability layer that affects control flow, user interaction, decision-making, and system behavior. That means architects and CTOs need to treat it like any other foundational shift, just like we did with microservices, cloud, and event-driven systems.
A few things start to matter more:
You also need to design for change. Models will improve, tools will shift, prompts will evolve. Your architecture needs to handle that fluidity without breaking downstream systems.
And finally, there’s the organizational side. AI isn’t just a tech concern, it’s also a cross-functional one. Security, compliance, product, and support will all have opinions. The architecture has to make room for those voices.
These patterns aren’t theoretical. They’re showing up in production systems right now, including ours. At Catio, we’ve had to confront these patterns head-on. We’re building tools for enterprise architects, people who think in systems and ask hard questions. That means our architecture can’t just look good in a diagram. It has to hold up under real-world complexity.
We use multi-agent workflows to reason about cloud environments, dependencies, and architecture tradeoffs. Each agent has its own job: interpreting topology, surfacing risks, generating recommendations. They communicate, coordinate, and occasionally get into disagreements (we’ve found that’s a feature, not a bug.)
To support that, we’ve leaned into patterns like LLM-as-interface and AI-orchestrated workflows. But we’ve also invested heavily in infrastructure around the models, things like routing, memory, context retrieval, and tool execution.
Architecture is evolving. Not because we’re chasing hype, but because we’ve unlocked new capabilities, and with them, new responsibilities. It’s on us to make sure the systems we build with AI are not just clever, but understandable, maintainable, and aligned with the needs of the people using them.
If that’s something you're working through too, check out what we’re building at catio.tech. And if you’re already deep in this space, wrangling prompts, agents, and patterns, then we should talk.