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AI & ML OpsLast reviewed 2026-09-20

LLMOps

Operating applications built on large language models you mostly do not control: provider and version management, evaluation harnesses, cost and latency per request, guardrails, and a plan for the day the model changes underneath you.

Overview

Read the full LLMOps guidance
WHAT IT IS LLMOps is the discipline of running production applications on top of large language models, usually ones operated by someone else. It covers provider and model-version management, evaluation harnesses that catch quality regressions, latency and cost per request, guardrails on input and output, fallback behaviour when a provider degrades, and the privacy question of what leaves your boundary with each call. **Not this:** LLMOps is not PromptOps: it owns the whole application around the model — providers, versions, evaluation, cost, guardrails and fallback — of which prompt management is one part. WHY IT EXISTS You do not control the most important dependency in the system. The model can be updated, deprecated, rate-limited or repriced by a third party on their schedule, and the same input can produce different output on two consecutive calls. Traditional deployment safety assumes a deterministic artifact you ship; here the artifact changes without a deploy. LLMOps exists because that inverts the usual assumptions about what a release is and what a regression looks like. WHEN TO USE IT Adopt it the moment an LLM sits in a user-facing path. Even a small feature needs version pinning, a cost ceiling and a defined behaviour for provider failure — those three absences account for most early production incidents in this space. WHO OWNS IT The product engineering team that ships the feature owns its behaviour end to end, including its failure modes; outsourcing the model does not outsource the accountability. Whoever owns the provider relationship owns quota, pricing and deprecation notices. Security and privacy review what is sent to the provider, which is a /privacyops question as much as an engineering one. The product owner owns the quality bar and the decision to disable a feature that falls below it. WHAT GOOD LOOKS LIKE The model and version in use are pinned and recorded, and a provider-side change is detected by your evaluation suite rather than by users. An evaluation set of real cases runs before every release and after provider changes, with a threshold that blocks a regression. Cost and latency are measured per request and per feature, with an alert before the bill becomes the incident. Output passes guardrails appropriate to the risk, and there is a defined, tested behaviour when the provider is slow or down — usually degrading to something honest rather than failing opaquely. What is sent to the provider is documented and defensible. HOW TO IMPLEMENT Pin the model version and record it with every response; without that, no regression is diagnosable. Build a small evaluation set from real cases early — fifty representative examples beat a sophisticated harness that does not exist — and run it in the pipeline. Add per-request cost and latency telemetry next, because this is where surprises are financial. Define and test the fallback path. Add guardrails proportionate to the risk of the output. Treat prompt changes with the versioning discipline in /promptops, and if the application retrieves context, the retrieval side belongs to /ragops. HOW TO ASSESS YOURSELF Ask which model version is in production and how you would know if it changed. Ask what your evaluation suite would catch and what it would miss. Ask what a user sees when the provider times out. Ask what the feature costs per thousand requests. Take the scored self-assessment at /assess, then plan the gaps with /roadmaps.

Capabilities

  • Evaluation harness

    A set of real cases run before every release and after provider changes, with a threshold that blocks a quality regression.

  • Inference cost management

    Measuring and bounding spend per request and per feature, with an alert that arrives before the invoice does.

  • Output guardrails

    Checks on model input and output proportionate to the risk of the output, applied before it reaches a user or a downstream system.

  • Provider and version pinning

    Fixing and recording which model version serves production, so a vendor-side change is detectable rather than an unexplained quality shift.

  • Provider failure fallback

    Defined and tested behaviour when the provider is slow, rate-limited or down — degrading honestly rather than failing opaquely.

  • Request telemetry

    Per-request latency, token and cost instrumentation attributed to the feature that caused it.

Practices

  • Evaluation set curation

    Growing a fixed set of real cases — especially the ones that have already caused complaints — and keeping it small enough that it actually runs.

  • Provider change drill

    Rehearsing a model deprecation or provider outage before the vendor schedules one for you, and measuring how long switching takes.

Metrics

  • Cost per thousand requests

    Inference spend attributed to a feature, which is the unit in which LLM surprises arrive.

    Unit: USD per 1000 requests. Good direction: down.

  • Evaluation pass rate

    Share of the evaluation set meeting its quality bar on the current model and prompt versions.

    Unit: percent. Good direction: up.

  • Fallback success rate

    Share of provider failures where the defined fallback produced an acceptable user outcome rather than an error.

    Unit: percent. Good direction: up.

  • p95 inference latency

    Ninety-fifth percentile end-to-end response time for a model-backed request, including retries and fallbacks.

    Unit: milliseconds. Good direction: down.

Tools

  • Guardrails AI

    Framework for validating and constraining model input and output against declared rules before it reaches a user.

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  • LangSmith

    Tracing, dataset and evaluation tooling for LLM applications, including prompt-level comparison runs.

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  • Langfuse

    Open-source observability, prompt management and evaluation for LLM applications, including retrieval traces.

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  • LiteLLM

    Provider-abstraction proxy for LLM calls, commonly used for version pinning, fallback routing and per-feature cost attribution.

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Architecture patterns

Reference architectures and their trade-offs live in the blueprints library.

Maturity

  1. L1 ReactiveA model version nobody pinnedrequired stage

    The application calls whatever the provider currently serves; quality shifts are unexplained because the dependency changed without a deploy.

  2. L2 RepeatableVersion pinned and recorded with each responserequired stage

    The model and version in use are fixed and logged per request, making a provider-side change detectable rather than mysterious.

  3. L3 StandardizedAn evaluation set runs before every release

    Real cases are checked against a threshold in the pipeline and after provider changes, so regressions are caught before users find them.

  4. L4 MeasuredCost, latency and fallback behaviour are measured

    Spend and latency are attributed per feature with alerting, and the defined degraded path has a measured success rate.

  5. L5 OptimizedProvider change is a rehearsed event

    Deprecations and outages have been drilled, switching time is known, and the evaluation suite gates the migration.

Maturity for llmops is measured, not guessed — every score traces to your answers. See how maturity is scored.

Put it to work

Sources