If vLLM already solved LLM serving, why did SGLang appear?
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Training a model is a project. Running it is a bill that arrives every month.
That difference now shapes most AI budgets. Deloitte’s 2026 Technology, Media and Telecommunications Predictions puts inference at about two-thirds of the world’s AI compute in 2026. In 2023 it was about a third. Inference has overtaken training as the larger workload, and Deloitte expects the market for inference-optimized chips to pass $50 billion this year.

The teams feeling this first are the ones that went from pilot to production. A pilot serves a few internal users on a shared API. Production serves customers, at their volumes, with a latency target and a cost attached to every request.
Inference as a service is how most teams cross that line without building GPU infrastructure themselves.
Inference is the stage where a trained model does its job. It takes new input and returns an output: a prediction, a classification, a summary, an answer, a transcript.
Training happens once, or a few times, on a large cluster. Inference happens on every request, for as long as the application is live.
That is why the two run on opposite economics. Training is front-loaded and finite. Inference is recurring, and it grows with adoption. For most production applications, inference is where the majority of a model’s lifetime cost lands.
A provider runs the serving infrastructure. You call an endpoint. You supply the model and the traffic. The provider supplies the GPUs, the serving stack, the networking, the scaling, the monitoring, and the people who fix it when it breaks.
| One warning on the acronym. Inference as a service is often shortened to IaaS, which is already the abbreviation for Infrastructure as a Service. They sit at different layers. Infrastructure as a Service rents you the machine and leaves the serving stack to you. Inference as a service hands you a running model endpoint. Write both out in full and the procurement conversation gets easier. |
Here is the usual split of responsibility.
| The provider runs | You own |
| GPU capacity and the serving runtime | The model, its weights, and its version |
| Scaling, load balancing, and failover | Prompt design, retrieval, and application logic |
| Networking, storage, and the physical estate | Your data, and where it is allowed to live |
| Platform monitoring and support | Your latency and quality targets |
Three delivery models dominate. The difference between them matters more than the feature lists do.
| Shared / serverless | Dedicated endpoint | Self-managed on rented GPUs | |
| Time to first call | Minutes | Days | Weeks |
| Tail latency | Moves with other tenants | Yours to predict | Yours to engineer |
| Cost shape | Per token, scales with usage | Reserved capacity, unit cost falls with volume | Hourly GPU cost plus engineering time |
| Model version control | The provider decides | You decide | You decide |
| Operational load | Low | Low to medium | High |
| Best for | Prototypes, spiky traffic | Sustained production traffic | Custom serving stacks, research |
Most production teams land on the middle column, or move there once traffic becomes predictable.
Three numbers explain the shift.
Token volume is compounding. OpenRouter routes requests across model providers, so its volume is a useful public proxy for demand. It reported about 25 trillion tokens a week in May 2026, roughly five times its level six months earlier. Agents are a large part of that. One user action can trigger a dozen model calls when an agent plans, calls tools, and checks its own work.

The service market is growing faster than the hardware around it. Precedence Research sizes AI inference as a service at $23.4 billion in 2026, rising to $197.5 billion by 2035. That is a compound annual growth rate of about 26.8 percent. Grand View Research puts the wider AI inference market at roughly $113.5 billion in 2026, reaching about $255 billion by 2030.

Unit prices are falling while total spend climbs. Gartner expects inference on a one-trillion-parameter model to cost providers over 90 percent less by 2030 than it did in 2025. Budgets have still gone up. Gartner also forecasts worldwide AI spending at $2.59 trillion in 2026, a 47 percent increase. Lower prices per token pull more use cases into production, and the total grows anyway.

Published on-demand list prices give the order of magnitude for a GPU-hour. Nebius, one of the providers that publishes a full public rate card, lists H100 at $3.85, H200 at $4.50, B200 at $7.15, and B300 at $7.85 per GPU-hour as of July 2026 (Nebius public rate card, nebius.com/prices, verified 29 July 2026).

The rate card is the easy part. Three things move the bill more than the hourly price does.
Gartner reports that through 2028, at least half of generative AI projects will overrun their budgets. It attributes this to architecture choices and thin operational experience rather than to the price of compute.
Inference platforms look alike on a feature page. They behave very differently under production traffic.
| Sector | What runs as inference | What decides the deployment |
| Financial services | Fraud and risk scoring on every transaction; underwriting, KYC review, dispute handling | Millisecond latency budgets and RBI / SEBI supervision |
| Healthcare and life sciences | Imaging triage, clinical documentation, coding support | Patient data rules, and models that stay auditable |
| Retail and e-commerce | Recommendations, search ranking, catalog enrichment, support assistants | Cost per thousand requests, tracked by the business |
| Manufacturing and industrials | Vision inspection, predictive maintenance, anomaly detection | Proximity to the equipment; hybrid edge and cloud serving |
| Voice and multilingual | Speech recognition, translation, voice agents | A pause the user can hear is a failed interaction |

Neysa Velocis is an AI acceleration cloud built and run in India, and a SemiAnalysis ClusterMAX Recommended cloud. Teams run production inference on it when their workloads are latency-sensitive, volume-heavy, or supervised by an Indian regulator.
Proof. ITQ Technologies runs two production LLM services on Velocis. They interpret fragmented airline fare and refund rules in real time.
“By partnering with Neysa, we have finally moved past the latency and cost barriers of legacy infrastructure to a system that handles our scale with total reliability.”
Anil Porter, Chief Information Officer, ITQ Technologies
Four shifts are worth planning for.
The common thread: inference stops being an infrastructure decision and becomes an operating discipline. Measured, attributed, governed, and reviewed like any other production system.
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Cloud platforms have reshaped AI training—from costly GPU clusters to on-demand, pay-as-you-go infrastructure. With providers like AWS, Google Cloud, Azure, and specialised AI clouds like Neysa Velocis, organisations now scale faster, cut costs, and collaborate globally. From healthcare to manufacturing, cloud AI training is unlocking breakthroughs that were once impossible.
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