Note: This post focuses on when and why startups begin adopting a gateway in front of Microsoft Foundry. In a follow-up article, we’ll go into a technical deep dive, covering design decisions, operational tradeoffs, latency considerations, observability, and patterns used in production-scale environments.
Most teams don’t hit scaling challenges with Microsoft Foundry on day one.
Early on, things are simple. One or two applications call Foundry directly. Traffic is predictable. Model experimentation moves fast. Everything works, and there’s no reason to add extra layers.
Then adoption grows. More applications start calling the same models. Traffic becomes spiky. Teams want better visibility into usage. Questions about rate limits, authentication, and how to evolve models over time begin to surface.
This is usually the moment when teams start asking: “Do we need some kind of control layer in front of Foundry?”
The signals that start to show up
Across many startups, the same patterns tend to emerge as Foundry usage scales:
- Multiple clients and services calling the same Foundry endpoints
- The need for consistent rate limiting and access control
- A desire to evolve models or deployments without touching every client
- Limited visibility into who is calling what, and how often
None of these are problems at small scale. But together, they create friction as usage grows.
A pattern we often see working well
A common pattern at this stage is placing a gateway in front of Microsoft Foundry APIs.
Client applications call a single gateway endpoint, where policies such as authentication, rate limits, and routing are applied before requests are forwarded to Foundry model deployments.Rather than having every application talk directly to Foundry, teams introduce a control layer that sits between clients and Foundry.
On Azure, this is often implemented using API Management with GenAI capabilities.
This gateway does not replace Foundry. Foundry remains the model and AI platform. The gateway simply becomes the entry point for client traffic.
What this enables in practice
When teams introduce a gateway layer, a few things become much easier:
- A single, stable API surface for applications, even as models or deployments evolve
- Centralized throttling and authentication, instead of per-client logic
- Policy-based routing across models or backends without changing clients
- Improved request-level observability into usage patterns, latency, and errors
Importantly, this structure lets teams scale without slowing down experimentation. Model teams can continue to iterate, while platform concerns stay centralized.
What this pattern is not
It’s worth calling out what this approach is not:
- It’s not required on day one
- It’s not mandatory for every startup
- It’s not about adding complexity early
Many teams run successfully without a gateway for a long time. This pattern becomes useful when scale, team size, or operational needs make direct integrations harder to manage.
When teams usually consider this
From experience, teams tend to explore this pattern when:
- Foundry usage spans multiple applications or teams
- Rate limits and quotas need consistent enforcement
- There’s a desire to future-proof model or deployment changes
- Observability and governance start to matter more
If those conversations are already happening, it’s often a good time to look at a gateway approach.
How this looks on Azure
On Azure, this pattern is commonly implemented using:
- Azure API Management as the gateway
- AI-aware policies for rate limiting, routing, and governance
- Microsoft Foundry as the backend model platform
The architecture stays flexible. Teams can start simple and add capabilities over time as needs evolve.
Closing thoughts
This pattern is less about tooling and more about timing.
Adding a gateway too early can slow teams down. Adding it too late can make change painful. The right moment is usually when Foundry usage starts to feel like a shared platform rather than a single experiment.
For teams approaching that stage, a gateway can provide structure without taking away speed.
References
Microsoft