← back to writing

Infrastructure · · first published on LinkedIn

Serving AI in Real-Time: Architecture for Low-Latency, High-Availability Inference

End-to-end serving architecture for real-time AI inference. Managed vs self-hosted, gRPC vs REST, edge vs centralised, the trade-offs that actually matter.

As I have said time and time again, in production environments, deploying a trained AI model is no longer a matter of saving a .pkl file and calling it a day. Real-time inference requires architectural discipline. This is especially true in latency-sensitive use cases like finance, healthcare, gaming, real-time bidding, or fraud detection, where every millisecond counts and system failures carry significant business risk.

The growing availability of open-source tools and managed platforms has certainly lowered the barrier to entry, but it has simultaneously raised expectations on throughput, observability, and user experience.

This article outlines an end-to-end serving architecture designed to meet low-latency constraints while maintaining high availability and scalability. My focus here is practical: what works, what scales, and what needs constant observation. Just like building a robust data governance framework is a journey, so is architecting for real-time AI inference. It is about building a foundation that will power your digital strategy.

The Orchestration Layer

The first crucial decision you face when venturing into real-time AI inference is whether to manage the serving infrastructure yourself or to leverage a managed solution. This choice is not trivial; it depends heavily on your organisation’s operational maturity, existing compliance requirements, and, critically, your performance constraints.

For many enterprise scenarios, managed model serving from platforms like Databricks Mosaic Model Serving, Azure ML Studios Endpoints, or Amazon SageMaker Endpoints provides a viable balance. These services abstract away a significant portion of the underlying infrastructure complexity. They handle automated scaling, SSL certificates, A/B testing, and version control, freeing your teams from much of the operational burden. They are typically suitable for workloads that can tolerate latencies in the range of ~50-150ms, offering a streamlined path to production without demanding deep DevOps expertise.

However, for organisations that demand stricter control over latency and require more aggressive optimisation, teams often turn to self-managed solutions built on Kubernetes with KServe. KServe is a Kubernetes-native serving framework that simplifies the deployment of machine learning models. It is a powerful tool, offering advanced features like scaling to zero, auto-scaling based on various metrics, version management, and sophisticated traffic management. The trade-off is increased operational overhead; managing Kubernetes and its ecosystem requires a dedicated and skilled team. But for mission-critical applications where every millisecond counts, the superior customisation and control it offers can be invaluable.

Compute Backbone

Once you have chosen your serving framework, the next critical step is architecting the computational backbone for your real-time inference. This dictates both performance and cost. Your serving infrastructure must align directly with your model size, expected Queries Per Second (QPS), and your target inference latency requirements.

The debate of how much of the infrastructure will be “on prem” is a lengthy one with its own intricacies. I will not delve into that at the moment, but I want to highlight its importance: we are talking about GPU vs CPU, horizontal vs vertical scaling, predictive scaling, cooldown periods, load balancing, concurrency management, and so on.

I want to emphasise that building out the right infrastructure for AI is not a one-time project; it is an ongoing journey of evaluation, adaptation, and optimisation. Your teams must constantly discuss it, preferably in a “chapter” or “guild” model. As CTOs and CDOs, our role is to ensure this foundation is not only robust and efficient today but also agile enough to embrace the innovations of tomorrow.

API Design

The API design defines how your applications interact with the deployed AI models. It is the handshake between your front-end experience and your intelligent backend. This interface must be stable, fast, and, ideally, backwards-compatible to ensure seamless updates and integrations.

RESTful APIs are the workhorse of the modern web and are widely adopted due to their simplicity, statelessness, and broad tooling support. They are perfectly suitable for many real-time inference scenarios.

However, for ultra-low latency, high-throughput, and streaming scenarios, gRPC presents a compelling alternative. Built on HTTP/2 and Protocol Buffers, gRPC offers binary serialisation (smaller payloads, less parsing overhead), multiplexing (multiple concurrent requests over a single TCP connection), and bidirectional streaming (critical for continuous data exchange like voice transcription or game telemetry).

For finance and gaming applications, where continuous updates or complex interactions are prevalent, gRPC can undeniably provide a performance edge over REST, often reducing end-to-end inference time considerably.

Network Latency

My last point is about the silent killer of real-time performance: network latency. Even with the fastest models and most optimised servers, if your data has to travel across continents, minimising round-trip time is absolutely critical.

For applications with extremely stringent latency requirements (autonomous systems, real-time industrial control, specific gaming scenarios like cloud gaming), Edge Computing is the answer. Deploying inference capabilities at the network edge, physically closer to the data source or end-user, drastically minimises round-trip times to central cloud data centres. This involves pushing model execution onto edge devices like IoT gateways, smart cameras, or local micro-data centres. This strategy not only slashes network latency but also enhances privacy and security by processing sensitive data locally.

Consider the impact of your model itself on network efficiency. Model Distillation and Quantisation are powerful techniques to create lightweight models. Distilled or quantised models offer several benefits: faster serialisation, lower memory footprints, and smaller binary sizes. These smaller models are inherently more network-efficient.

Advice for Teams Implementing AI

Real-time inference forces a powerful convergence of disciplines: ML engineering, backend infrastructure, and DevOps. In my experience, success depends far less on which specific model you choose and much more on how you serve it.

If you are embarking on AI implementation in your organisation, start by gaining a crystal-clear understanding of your specific latency budget and reliability targets. Do not guess; measure. Then, choose serving frameworks and infrastructure that are designed to make performance observable and reproducible. Design your serving APIs with future integration in mind, prioritising lean payloads and efficient serialisation.

And always, always plan for failure. Whether that is an unexpected spike in demand, a model crash, or upstream feature drift, anticipate these scenarios and build resilient mechanisms like circuit breakers or rules-based fallbacks.

Do not treat model deployment as the finish line. It is truly the beginning of a living, breathing system that must adapt, scale, and stay accountable. The possibilities that AI unlocks are immense, but realising that potential hinges on the strength and intelligence of the infrastructure that supports it.