Anyscale Alternatives for Ray Serve Model Serving
Connor Blier
Founding GTM
Anyscale Alternatives for Ray Serve Model Serving
The leading anyscale alternatives for ray serve model serving are KServe for Kubernetes-native teams, Together AI for a managed model API, and serverless GPU platforms like Cerebrium when you want fast autoscaling without running Ray yourself. The right pick depends on your infra appetite and latency targets.
TL;DR: the leading alternatives
If you are evaluating anyscale alternatives for ray serve model serving, three directions cover almost every team:
KServe - a Kubernetes-native serving layer for teams that already live in Kubernetes and want an open standard.
Together AI - a managed, full-stack model API when you want to consume open models without owning serving infrastructure at all.
Managed serverless GPU platforms (such as Cerebrium, Modal and Baseten) - when you want Ray Serve-style autoscaling and composition without running the cluster.
Ray Serve itself is open source and runs anywhere Ray runs, so "leaving Anyscale" rarely means rewriting your model code - it usually means changing who operates the platform underneath it.
Why teams evaluate alternatives to Anyscale for Ray Serve
Anyscale is the commercial home of Ray Serve, and it is a strong one: it advertises up to 60% higher QPS with its optimized Ray Serve versus open source, Replica Compaction that "automatically migrates replicas to fewer nodes... with zero downtime," and one-minute node scale-up versus a "competitors' 5+ minute average." Adoption backs the story - Anyscale reports Ray Serve usage grew over 600% since January 2023.
So why look elsewhere? Usually one of three reasons. First, platform ownership: Ray Serve is open source and, per the Ray docs, "you can run it anywhere Ray can: on your laptop, Kubernetes, any major cloud provider, or even on-premise" - so some teams want to avoid a vendor for the control plane. Second, fit: Ray Serve, as the docs state plainly, "is not a full-fledged ML Platform" and "lacks the functionality for managing the lifecycle of your models," so teams sometimes want a platform that supplies more of that. Third, operational cost - running Ray is a platform-team commitment, and not every org wants to staff it.
How to evaluate a Ray Serve serving platform
A few criteria separate the options for a VP of Engineering:
Who runs the control plane? Self-managed open-source Ray Serve, managed Ray (Anyscale), or a non-Ray platform that gives you the same outcomes.
Cold start and scale-up speed. For spiky LLM traffic this dominates both latency and cost. In our testing of a TensorRT-LLM Llama 3 8B engine, we measured a
~10-15scold start to load the model into GPU memory - the kind of number you should benchmark on any platform before committing.Latency under real load. Our benchmarks of vLLM, SGLang and TensorRT on a single H100 produced a lowest TTFT of 123ms and peak throughput of 460 tokens/sec - measured as the total roundtrip to the platform, not a vendor spec sheet. The full methodology and curves matter more than any single number.
Model composition and multi-model packing. Ray Serve's strengths are composition, multiplexing and co-locating models of different sizes; evaluate whether an alternative preserves multiple models on one GPU.
Lifecycle and SLOs. Versioning, canary rollout and goodput/latency SLOs are where a bare serving library ends and a platform begins.
The top alternatives, compared
| Option | What it is | Best for | Who operates it |
|---|---|---|---|
| Open-source Ray Serve | The serving library, self-hosted | Full control, no vendor | You |
| Anyscale | Managed, optimized Ray Serve | Ray-native teams wanting speed | Anyscale |
| KServe | Kubernetes-native CRD serving | Kubernetes shops, open standard | You (on K8s) |
| Together AI | Managed model API | Consuming open models, no infra | Together |
| Serverless GPU platforms | Managed autoscaling GPUs | Spiky LLM traffic, small infra team | The provider |
KServe
KServe "provides a Kubernetes Custom Resource Definition for serving predictive and generative machine learning models" and "encapsulates the complexity of autoscaling, networking, health checking, and server configuration." One writeup frames it well: "Think of KServe as KNative or OpenFaaS, but, for ML applications." It recently joined CNCF as an incubating project, which signals its standing as an open standard. KServe is the natural pick when Kubernetes is already your platform and you want open governance rather than a single vendor.
Together AI
At the opposite end, Together AI is a "full-stack AI platform" offering production inference with access to dozens of models via a managed API. If your goal is to call open models without owning a serving stack at all, a model API removes the Ray operations question entirely. The trade-off is less control over composition and routing. For teams serving their own fine-tunes, compare against Together AI alternatives for fine-tuned LLM inference.
Managed serverless GPU platforms
Serverless GPU platforms sit between "run Ray yourself" and "call an API." They give you autoscaling, fast scale-up and model deployment without a cluster to babysit. Production proof: DistilLabs runs up to 150 requests per second per model at peak with multiple models deployed concurrently on Cerebrium. This is the lane to evaluate for spiky, unpredictable LLM traffic.
Managed vs. self-managed Ray Serve
Self-managed Ray Serve maximizes control - you own the serving topology, framework, autoscaling and bill - and it is the right call when compliance, custom routing or deep throughput tuning demand it, and you have the platform team to run it. Managed options (Anyscale, or a serverless GPU platform) trade some control for not staffing that team. Anyscale's own framing is that "Anyscale Services manages deployment infrastructure and integrations, and is heavily production-tested." The honest question is whether Ray specifically is a requirement, or just the path you started on.
When Anyscale is still the right choice
Stay on Anyscale when you are already Ray-native across training and serving, when you need its optimized-QPS and Replica Compaction economics at scale, or when distributed Ray workloads beyond serving are core to your stack. Samsara, for instance, reported a ~50% reduction in total ML inferencing costs using Ray Serve. If Ray is the center of gravity, the managed Ray platform is the lowest-friction answer.
Recommendations by scenario
Kubernetes shop wanting an open standard: KServe.
Consuming open models, no infra appetite: Together AI.
Spiky LLM traffic, small platform team: a serverless GPU platform.
Deep Ray investment and throughput tuning: stay on Anyscale.
Avoiding hyperscaler lock-in generally: see our AWS/GCP/Azure alternatives.
Frequently asked questions
- Do I have to rewrite my Ray Serve code to leave Anyscale?
- Usually not. Ray Serve is open source and, per the Ray docs, runs anywhere Ray runs - your laptop, Kubernetes, any major cloud, or on-premise. Leaving Anyscale typically means changing who operates the control plane, not rewriting your serving logic.
- Is KServe a drop-in replacement for Ray Serve?
- Not drop-in - it is a different, Kubernetes-native model. KServe provides a Custom Resource Definition that handles autoscaling, networking and health checking on Kubernetes. It suits teams already standardized on Kubernetes who want an open CNCF-governed standard rather than Ray specifically.
- When is a managed API like Together AI the better choice?
- When you want to consume open models without owning any serving infrastructure. Together AI is a full-stack platform offering inference across dozens of models via API. You give up composition and routing control in exchange for removing all Ray operations.
- What should I benchmark before switching?
- Cold start, scale-up time, TTFT and throughput under your real load. In our testing a TensorRT-LLM Llama 3 8B engine took ~10-15s to cold-start into GPU memory, and we measured a 123ms lowest TTFT on an H100 - measure the equivalent on each platform you consider.
Get started with Cerebrium
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Sources
- anyscale.com
“up to 60% higher QPS serving with optimized version of Ray Serve (vs. open source Ray Serve)”
Anyscale's optimized Ray Serve performance claim.
- anyscale.com
“Anyscale's Replica Compaction automatically migrates replicas to fewer nodes in order to optimize resources and reduce costs—with zero downtime.”
Replica Compaction cost feature.
- anyscale.com
“Anyscale nodes scale up in one minute, compared to competitors' 5+ minute average.”
Scale-up speed claim.
- anyscale.com
“~50% reduction in total ML inferencing costs for Samsara”
Customer cost-reduction proof point.
- anyscale.com
“Since January 2023, the usage for Ray Serve and Anyscale Services has grown over 600%.”
Adoption growth figure.
- anyscale.com
“Anyscale Services manages deployment infrastructure and integrations, and is heavily production-tested.”
What managed Anyscale provides.
- docs.ray.io
“Ray Serve is not tied to any specific machine learning library or framework, but rather provides a general-purpose scalable serving layer. Because it's built on top of Ray, you can run it anywhere Ray can: on your laptop, Kubernetes, any major cloud provider, or even on-premise.”
Ray Serve portability / no lock-in.
- docs.ray.io
“Ray Serve is not a full-fledged ML Platform. Compared to these other offerings, Ray Serve lacks the functionality for managing the lifecycle of your models, visualizing their performance, etc.”
Ray Serve is a serving library, not a platform.
- kserve.github.io
“KServe provides a Kubernetes Custom Resource Definition for serving predictive and generative machine learning models. It encapsulates the complexity of autoscaling, networking, health checking, and server configuration to bring cutting edge serving features to your ML deployments.”
What KServe is.
- kserve.github.io
“KServe has joined CNCF!”
KServe CNCF incubating status.
- ravishtiwari.medium.com
“Think of KServe as KNative or OpenFaaS, but, for ML applications.”
Analogy framing KServe.
- together.ai
“Full-stack AI platform, powered by cutting-edge research.”
Together AI positioning.
- cerebrium.ai
“This code will run on every cold start and takes roughly ~10-15s to load the model into GPU memory.”
First-hand cold-start measurement.
- cerebrium.ai
“From our tests, it seems that vLLM is the best framework for use cases looking for the lowest TTFT of 123ms which is extremely quick if you take into consideration network latency.”
First-hand TTFT benchmark.
- cerebrium.ai
“As for throughput use cases, it seems SGLang was a clear winner achieving a throughput of 460 tokens per second on a batch size of 64.”
First-hand throughput benchmark.
- cerebrium.ai
“The following benchmark was done with 256 input tokens on 1xH100 of batch size 1. This was the total roundtrip time of a request made to the Cerebrium platform.”
Benchmark methodology.
- cerebrium.ai
“Today, Distil Labs runs up to 150 requests per second per model during high-traffic periods, with multiple models deployed concurrently.”
Production scale proof point on Cerebrium.