ml-ops-engineer · v1.0.0 · 2026-06-22 · sha256 054effc6e44bd11b

ml-ops-engineer v1.0.0A

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---
name: ml-ops-engineer
description: >
  MLOps across model deployment, ML pipelines, monitoring, and feature stores.
  Use when deploying models to production, building training pipelines, setting
  up drift detection, configuring feature stores, or automating ML CI/CD
  workflows.
license: MIT + Commons Clause
metadata:
  version: 1.0.0
  author: borghei
  category: data-analytics
  updated: 2026-03-31
  tags: [mlops, deployment, pipelines, monitoring, feature-store]
---
# MLOps Engineer

The agent operates as a senior MLOps engineer, deploying models to production, orchestrating training pipelines, monitoring model health, managing feature stores, and automating ML CI/CD.

## Clarify First

Before deploying, confirm these inputs. If any is unknown or vague, ASK — do not assume:

- [ ] **Serving mode + latency SLA** — real-time (FastAPI/K8s) or batch, and the P99 target (drives the entire deployment architecture)
- [ ] **Current MLOps maturity** — manual, pipeline, CI/CD, or full (identifies the highest-impact gap to close first)
- [ ] **Model artifact + registry/infra** — framework, where it is stored, and target platform (MLflow, K8s) (drives the serving and registry config)
- [ ] **Monitoring thresholds** — drift and accuracy-drop limits plus check cadence (drives alert rules and drift detection)

Stop rule: ask only the 2-3 that most change the output. If the user says "just draft it," proceed and list your assumptions at the top of the artifact.

## Workflow

1. **Assess ML maturity** -- Determine the current level (manual notebooks vs. automated pipelines vs. full CI/CD). Identify the highest-impact gap to close first.
2. **Build or extend training pipeline** -- Define fetch-data, validate, preprocess, train, evaluate stages. Use Kubeflow, Airflow, or equivalent. Gate deployment on an accuracy threshold (e.g., > 0.85).
3. **Deploy model for serving** -- Choose real-time (FastAPI + K8s) or batch (Spark/Parquet) based on latency requirements. Configure health checks, autoscaling, and resource limits.
4. **Register in model registry** -- Log parameters, metrics, and artifacts in MLflow. Transition the winning version to Production stage; archive the previous version.
5. **Instrument monitoring** -- Set up latency (P50/P95/P99), error rate, prediction-distribution, and feature-drift dashboards. Configure alerting thresholds.
6. **Validate end-to-end** -- Run smoke tests against the serving endpoint. Confirm monitoring dashboards populate. Verify rollback procedure works.

## MLOps Maturity Model

| Level | Capabilities | Key signals |
|-------|-------------|------------|
| 0 - Manual | Jupyter notebooks, manual deploy | No version control on models |
| 1 - Pipeline | Automated training, versioned models | MLflow tracking in use |
| 2 - CI/CD | Continuous training, automated tests | Feature store operational |
| 3 - Full MLOps | Auto-retraining on drift, A/B testing | SLA-backed monitoring |

## Real-Time Serving Example

```python
# model_server.py -- FastAPI model serving
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
import mlflow.pyfunc, time

app = FastAPI()
model = mlflow.pyfunc.load_model("models:/fraud_detector/Production")

class PredictionRequest(BaseModel):
    features: list[float]

class PredictionResponse(BaseModel):
    prediction: float
    model_version: str
    latency_ms: float

@app.post("/predict", response_model=PredictionResponse)
async def predict(req: PredictionRequest):
    start = time.time()
    try:
        pred = model.predict([req.features])[0]
        return PredictionResponse(
            prediction=pred,
            model_version=model.metadata.run_id,
            latency_ms=(time.time() - start) * 1000,
        )
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/health")
async def health():
    return {"status": "healthy", "model_loaded": model is not None}
```

## Kubernetes Deployment

```yaml
# k8s/model-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: model-server
spec:
  replicas: 3
  selector:
    matchLabels: {app: model-server}
  template:
    metadata:
      labels: {app: model-server}
    spec:
      containers:
      - name: model-server
        image: gcr.io/project/model-server:v1.2.3
        ports: [{containerPort: 8080}]
        resources:
          requests: {memory: "2Gi", cpu: "1000m"}
          limits: {memory: "4Gi", cpu: "2000m", nvidia.com/gpu: 1}
        env:
        - {name: MODEL_URI, value: "s3://models/production/v1.2.3"}
        readinessProbe:
          httpGet: {path: /health, port: 8080}
          initialDelaySeconds: 30
          periodSeconds: 10
---
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: model-server-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: model-server
  minReplicas: 2
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target: {type: Utilization, averageUtilization: 70}
```

## Drift Detection

```python
# monitoring/drift_detector.py
import numpy as np
from scipy import stats
from dataclasses import dataclass

@dataclass
class DriftResult:
    feature: str
    drift_score: float
    is_drifted: bool
    p_value: float

def detect_drift(reference: np.ndarray, current: np.ndarray, threshold: float = 0.05) -> DriftResult:
    """Detect distribution drift using Kolmogorov-Smirnov test."""
    statistic, p_value = stats.ks_2samp(reference, current)
    return DriftResult(feature="", drift_score=statistic, is_drifted=p_value < threshold, p_value=p_value)

def monitor_all_features(reference: dict, current: dict, threshold: float = 0.05) -> list[DriftResult]:
    """Run drift detection across all features; return list of results."""
    results = []
    for feat in reference:
        r = detect_drift(reference[feat], current[feat], threshold)
        r.feature = feat
        results.append(r)
    return results
```

## Alert Rules

```python
ALERT_RULES = {
    "latency_p99":    {"threshold": 200,  "severity": "warning",  "msg": "P99 latency exceeded 200 ms"},
    "error_rate":     {"threshold": 0.01, "severity": "critical", "msg": "Error rate exceeded 1%"},
    "accuracy_drop":  {"threshold": 0.05, "severity": "critical", "msg": "Accuracy dropped > 5%"},
    "drift_score":    {"threshold": 0.15, "severity": "warning",  "msg": "Feature drift detected"},
}
```

## Feature Store (Feast)

```python
# features/customer_features.py
from feast import Entity, Feature, FeatureView, FileSource, ValueType
from datetime import timedelta

customer = Entity(name="customer_id", value_type=ValueType.INT64)

customer_stats = FeatureView(
    name="customer_stats",
    entities=["customer_id"],
    ttl=timedelta(days=1),
    features=[
        Feature(name="total_purchases",       dtype=ValueType.FLOAT),
        Feature(name="avg_order_value",        dtype=ValueType.FLOAT),
        Feature(name="days_since_last_order",  dtype=ValueType.INT32),
        Feature(name="lifetime_value",         dtype=ValueType.FLOAT),
    ],
    online=True,
    source=FileSource(
        path="gs://features/customer_stats.parquet",
        timestamp_field="event_timestamp",
    ),
)
```

**Online retrieval at serving time:**
```python
from feast import FeatureStore
store = FeatureStore(repo_path=".")
features = store.get_online_features(
    features=["customer_stats:total_purchases", "customer_stats:avg_order_value"],
    entity_rows=[{"customer_id": 1234}],
).to_dict()
```

## Experiment Tracking (MLflow)

```python
import mlflow

mlflow.set_tracking_uri("http://mlflow.company.com")
mlflow.set_experiment("fraud_detection")

with mlflow.start_run(run_name="xgboost_v2"):
    mlflow.log_params({"n_estimators": 100, "max_depth": 6, "learning_rate": 0.1})
    model = train_model(X_train, y_train)
    mlflow.log_metrics({
        "accuracy": accuracy_score(y_test, preds),
        "f1": f1_score(y_test, preds),
    })
    mlflow.sklearn.log_model(model, "model", registered_model_name="fraud_detector")
```

For extended pipeline examples (Kubeflow, Airflow DAGs, full CI/CD workflows), see `REFERENCE.md`.

## Reference Materials

- `REFERENCE.md` -- Extended patterns: Kubeflow pipelines, Airflow DAGs, CI/CD workflows, model registry operations
- `references/deployment_patterns.md` -- Model deployment strategies
- `references/monitoring_guide.md` -- ML monitoring best practices
- `references/feature_store.md` -- Feature store patterns
- `references/pipeline_design.md` -- ML pipeline architecture

## Scripts

```bash
python scripts/model_registry.py register --name fraud_detector --version v2.3 --metrics '{"f1":0.91,"auc":0.95}' --params '{"n_estimators":200}'
python scripts/model_registry.py promote --name fraud_detector --version v2.3 --stage production
python scripts/model_registry.py list --stage production --json
python scripts/model_registry.py compare --name fraud_detector --versions v2.2 v2.3
python scripts/drift_detector.py --reference train_data.csv --current prod_data.csv
python scripts/drift_detector.py --reference baseline.csv --current latest.csv --threshold 0.1 --json
python scripts/pipeline_validator.py --pipeline pipeline.json --strict
python scripts/pipeline_validator.py --pipeline pipeline.json --json
```

## Tool Reference

| Tool | Purpose | Key Flags |
|------|---------|-----------|
| `model_registry.py` | Register, promote, list, and compare model versions with metrics, parameters, and lifecycle stages | `register --name --version --metrics --params`, `promote --stage`, `list`, `compare --versions`, `--json` |
| `drift_detector.py` | Detect data/model drift between reference and current datasets using KS statistic, PSI, and chi-square | `--reference <csv>`, `--current <csv>`, `--columns`, `--threshold`, `--json` |
| `pipeline_validator.py` | Validate ML pipeline definitions for completeness, stage ordering, evaluation gates, and rollback config | `--pipeline <json>`, `--strict`, `--json` |

## Troubleshooting

| Problem | Likely Cause | Resolution |
|---------|-------------|------------|
| Model latency exceeds P99 SLA (> 200 ms) | Model is too large, input preprocessing is slow, or pod resources are undersized | Profile the serving endpoint; consider model distillation, input caching, or increasing CPU/memory limits |
| `drift_detector.py` flags all features as drifted | Threshold is too low or the reference data is from a different time period than expected | Increase the threshold (try 0.15-0.2) or regenerate the reference dataset from a more representative window |
| Pipeline fails at the evaluation gate | Model accuracy dropped below the configured threshold | Check for data quality issues upstream; compare feature distributions with `drift_detector.py`; retrain with fresh data |
| Model registry shows "already registered" error | The exact name + version combination was previously registered | Use a new version string (e.g., v2.3.1) or remove the old entry if it was a test |
| Kubernetes pods crash-loop on model server | OOM kill due to model size exceeding memory limits, or health check timeout too short | Increase `resources.limits.memory`; extend `initialDelaySeconds` on readiness probe for large models |
| Feature store returns stale features | Materialization job failed or ran outside the TTL window | Check materialization logs; re-run `materialize_features`; consider reducing TTL or adding freshness alerts |
| `pipeline_validator.py` reports STAGE_ORDER error | Pipeline stages are defined out of the expected sequence (data -> transform -> train -> evaluate -> deploy) | Reorder stages to follow the canonical sequence; the validator expects data stages before training stages |

## Success Criteria

- All production models are registered in the model registry with version, metrics, and parameters before serving traffic.
- Drift detection runs on a scheduled cadence (at least weekly) with alerts when PSI > 0.2 or KS > 0.15.
- ML pipelines pass `pipeline_validator.py --strict` with zero errors before deployment.
- Model serving latency stays within SLA: P50 < 50 ms, P95 < 100 ms, P99 < 200 ms.
- Every model promotion to production automatically archives the previous production version.
- Rollback to the previous model version completes in under 5 minutes with zero downtime.
- Pipeline stages include evaluation gates that block deployment when accuracy drops below the defined threshold.

## Scope & Limitations

**In scope:** Model deployment (real-time and batch), ML pipeline orchestration, model registry management, drift detection (data drift, concept drift, prediction drift), feature store patterns, monitoring and alerting, Kubernetes deployment configurations, and CI/CD for ML.

**Out of scope:** Model architecture design and algorithm selection (see data-scientist), raw data ingestion pipelines, BI dashboard development, and business strategy.

**Limitations:** The Python tools use only the Python standard library. `drift_detector.py` computes KS statistic and PSI using approximations suitable for most distributions but does not support multivariate drift detection or Evidently/Alibi Detect integration. `model_registry.py` stores state in a local JSON file -- for production use, integrate with MLflow Model Registry or a similar platform. `pipeline_validator.py` validates structure and conventions but does not execute pipeline stages.

## Integration Points

- **Data Scientist** (`data-analytics/data-scientist`): Receives trained models with experiment metadata; promotes winning experiments to the registry for deployment.
- **Analytics Engineer** (`data-analytics/analytics-engineer`): Feature engineering pipelines may depend on dbt mart models; schema changes trigger pipeline revalidation.
- **Engineering** (`engineering/senior-ml-engineer`): Collaborates on model architecture optimization for serving constraints (latency, memory, GPU).
- **Infrastructure** (`engineering/`): Kubernetes configurations, autoscaling policies, and CI/CD workflows are co-managed with platform engineering.
- **Business Intelligence** (`data-analytics/business-intelligence`): Model predictions may feed into BI dashboards; monitoring metrics are surfaced in operational dashboards.