ML & MLOps
What MLOps Looks Like in the Real World
Follow a model from versioned data and leakage-safe evaluation through a gated release, production monitoring and a deliberate retrain or rollback decision.
Reference architecture - illustrative, not a client deployment
Separate training, release decisions, serving and gated improvement.
- Complexity
- Intermediate
- Drawing
- Supplied
- MLOps
- Model Lifecycle
- Monitoring
- Release Engineering
- Machine Learning
Overview
This reference architecture is illustrative. It is not a record of a client deployment.
MLOps is the controlled path around a model, not a synonym for automated retraining. A versioned data snapshot first passes schema and quality checks and is split without leaking future or held-out information into training. Experiments produce candidate artifacts, but only a candidate that passes a held-out evaluation can be packaged with its preprocessing and lineage.
Release remains a separate decision. The registry provides a versioned package; a gate checks compatibility and acceptance criteria before a staged rollout sends traffic to the new inference version. Production monitoring then combines operational signals with predictions and delayed outcomes. A drift alert is evidence to investigate, not proof that a new training run will help. A person or governed review process can approve retraining, restore a compatible approved version, or leave the service unchanged.
A concrete example
A weekly demand model sees a category-code change upstream. Data validation stops the run before training. After the mapping is corrected, a candidate is evaluated against a time-ordered holdout. It passes the agreed criteria, is registered with its preprocessing package and receives a staged rollout. Later, outcome quality degrades while latency remains healthy. Reviewers inspect the signal and choose rollback because the previous package is still compatible; they do not automatically retrain on unverified data.
Common misconception
"Continuous training means every drift alert deploys a new model." Google and Microsoft architecture guidance separates data validation, model validation, release and monitoring. Automation can execute those controls, but it should not erase them.
Diagram & Walkthrough
Choose a declared scenario and step, or select a component by pointer, touch or keyboard. Playback starts only when you press Play and pauses when this panel leaves the screen.
Main walkthrough, step 1 of 6: Version and validate the data. idle.
Main walkthrough
The primary path through this reference architecture.
Active parts: Versioned data, Validation + leakage-safe split
Text walkthrough
This vertical reference remains readable without the interactive controls.
01Version and validate the data
An identifiable snapshot is checked and prepared for a reproducible run.
Active parts: Versioned data, Validation + leakage-safe split
02Train without leakage
Training receives only the appropriate partition and its preprocessing definition.
Active parts: Validation + leakage-safe split, Training + experiments
03Evaluate a candidate
The candidate is tested against held-out evidence and declared acceptance criteria.
Active parts: Training + experiments, Held-out evaluation
04Register an approved package
A passing candidate is registered with preprocessing and then presented to the release gate.
Active parts: Held-out evaluation, Model + preprocessing registry, Release gate + staged rollout
05Roll out and serve
The approved package is rolled out, and its predictions and outcomes become observable by version.
Active parts: Release gate + staged rollout, Production inference, Quality + drift monitoring
06Review improvement signals
A reviewer interprets the signal and explicitly authorizes a new training cycle when justified.
Active parts: Quality + drift monitoring, Retrain or rollback review, Validation + leakage-safe split
Connections
- Versioned snapshotVersioned data to Validation + leakage-safe splitdata
- Train split + preprocessingValidation + leakage-safe split to Training + experimentsdata
- Candidate artifactTraining + experiments to Held-out evaluationdata
- Passing candidateHeld-out evaluation to Model + preprocessing registrycontrol
- Versioned packageModel + preprocessing registry to Release gate + staged rolloutcontrol
- Approved releaseRelease gate + staged rollout to Production inferencecontrol
- Predictions + outcomesProduction inference to Quality + drift monitoringfeedback
- Quality or drift signalQuality + drift monitoring to Retrain or rollback reviewfeedback
- Approved retrainingRetrain or rollback review to Validation + leakage-safe splitcontrol
- Restore approved versionRetrain or rollback review to Release gate + staged rolloutcontrol
- Evaluation failedHeld-out evaluation to Retrain or rollback reviewcontrol
Components
Versioned datadata
Keeps an identifiable training snapshot and the lineage needed to reproduce it.
Responsibilities
- Version training inputs and labels
- Retain lineage and access boundaries
Inputs
- Authorized source data
- Observed labels
Outputs
- Versioned snapshot
Risks
- Stale or incorrectly joined labels
- A schema change hidden inside the same version
Validation + leakage-safe splitdeterministic
Validates the snapshot and creates training and held-out partitions without fitting transformations on future data.
Responsibilities
- Check schema and data quality
- Create leakage-safe splits and preprocessing inputs
Inputs
- Versioned snapshot
Outputs
- Training split
- Held-out split
- Preprocessing definition
Risks
- Target or temporal leakage
- Preparation logic that differs from serving
Training + experimentsmodel
Fits candidate models under recorded code, configuration and data versions.
Responsibilities
- Run reproducible experiments
- Produce candidate artifacts and training metrics
Inputs
- Training split and preprocessing
- Versioned training code and configuration
Outputs
- Candidate model artifact
- Experiment metadata
Risks
- Irreproducible environments
- Optimizing repeatedly against the holdout set
Held-out evaluationdeterministic
Tests the candidate against declared quality, safety and compatibility criteria on held-out data.
Responsibilities
- Compare against baselines and acceptance criteria
- Reject candidates that do not pass
Inputs
- Candidate model artifact
- Held-out split
Outputs
- Passing candidate
- Or evaluation failure
Risks
- A metric that does not represent the business outcome
- A contaminated holdout set
Model + preprocessing registrydata
Stores the approved model together with compatible preprocessing and traceable metadata.
Responsibilities
- Keep immutable package versions
- Link artifacts to their data, code and evaluation
Inputs
- Passing candidate
- Preprocessing package and lineage
Outputs
- Versioned release package
Risks
- Model and preprocessing versions become mismatched
- Missing lineage prevents reproduction
Release gate + staged rolloutdeterministic
Checks the registered package, records approval and controls staged promotion or restoration.
Responsibilities
- Enforce release criteria
- Support a controlled rollout and rollback
Inputs
- Versioned release package
- Release approval or rollback choice
Outputs
- Approved release
Risks
- A bypassed release gate
- Rollback to an incompatible feature contract
Production inferencemodel
Serves predictions from the approved model and preprocessing version.
Responsibilities
- Apply the released package consistently
- Attach model version to predictions
Inputs
- Approved release
- Production feature values
Outputs
- Predictions with model version
Risks
- Training-serving skew
- Latency or availability outside the decision budget
Quality + drift monitoringdeterministic
Combines service telemetry, feature distributions, predictions and available outcomes by version.
Responsibilities
- Detect operational and statistical changes
- Produce reviewable signals rather than automatic conclusions
Inputs
- Predictions
- Outcomes
- Service telemetry
Outputs
- Quality or drift signal
Risks
- Delayed labels hide degradation
- Noisy thresholds create alert fatigue
Retrain or rollback reviewhuman
Interprets evidence and authorizes retraining, rollback or no change.
Responsibilities
- Investigate evaluation and monitoring signals
- Choose a controlled corrective action
Inputs
- Quality or drift signal
- Evaluation failure
Outputs
- Approved retraining
- Rollback decision
- Or no change
Risks
- Treating drift as proof that retraining helps
- Restoring an obsolete package without compatibility checks
Scenario reference
Candidate rejected
Keep the previously approved model available.
01Assess the candidate
The candidate reaches held-out evaluation but does not satisfy the release criteria.
Active parts: Training + experiments, Held-out evaluation
02Keep the candidate out of production
The failed result goes to review while the approved production version remains available.
Active parts: Held-out evaluation, Retrain or rollback review
Production rollback
Restore a compatible approved model and preprocessing package.
01Observe a production problem
Versioned predictions and outcomes reveal a quality or operational concern.
Active parts: Production inference, Quality + drift monitoring
02Review the signal
The signal is investigated before a compatible approved package is selected.
Active parts: Quality + drift monitoring, Retrain or rollback review
03Restore the approved version
The selected package returns through the release gate and is rolled out under control.
Active parts: Retrain or rollback review, Release gate + staged rollout, Production inference
Design Decisions
- Version data, code, features, preprocessing and model artifacts together.
- Fit preprocessing on training data only and preserve a genuinely held-out evaluation set.
- Promote through an explicit gate and retain a tested rollback package.
- Monitor data, service behavior and real-world quality by model version.
Risks & Trade-offs
Leakage can make offline metrics misleading. Training-serving transformations can diverge. Delayed or biased labels can trigger noisy alerts, and a technically compatible rollback may still restore stale behavior. More automation improves repeatability but adds pipeline, lineage and operational maintenance.
When to Use / Not Use
Use this pattern for models that are retrained or released repeatedly and influence production decisions. A small, rarely changed offline model may need versioning and review without a full continuous-delivery platform. Do not automate releases when valid evaluation data or rollback compatibility is unavailable.

