Data Pipeline Spec Skill

This skill produces a complete data pipeline specification covering sources, transformations, destinations, scheduling, SLAs, error handling, data quality checks, and monitoring requirements. Output is ready for engineering handoff or architecture review.

Required Inputs

Ask the user for these if not provided:

• Pipeline purpose — what business question or workflow does this pipeline serve?
• Source systems — where does data come from? (databases, APIs, files, event streams)
• Destination — where does data land? (data warehouse, data lake, downstream DB, reporting tool)
• Transformation type — ETL (transform before loading) or ELT (load raw, transform in warehouse)?
• Frequency / SLA — how often must data be fresh? (real-time / hourly / daily / weekly)
• Volume estimate — approximate rows/events per run
• Data quality requirements — completeness, deduplication, freshness, schema enforcement
• Team or stack — any specific tools in use? (Airflow, dbt, Fivetran, Spark, Kafka, etc.)

Output Structure

Data Pipeline Spec: [Pipeline Name]

Purpose: [One sentence — what decision or workflow does this pipeline enable?] Type: [ETL / ELT / Streaming / Batch] Owner: [Team or individual] Version: [1.0] Date: [Date] Status: [Draft / Under Review / Approved]

1. Overview

[2–3 sentences describing the pipeline end-to-end: what data moves, from where to where, at what cadence, and why.]

Architecture diagram (text):

[Source A] ──┐
[Source B] ──┤──► [Ingestion Layer] ──► [Transform Layer] ──► [Destination] ──► [Consumers]
[Source C] ──┘

2. Sources

Incremental key (if applicable): [The column used to identify new or changed records — e.g. updated_at, event_id]

Authentication: [API key / OAuth / IAM role / connection string — note where credentials are stored]

3. Ingestion Layer

Tool: [Fivetran / Airbyte / Kafka Connect / custom script / dbt source]

Ingestion method:

• Full extract (full table refresh each run)
• Incremental extract (only new/changed rows since last run)
• CDC (change data capture from database transaction log)
• Event streaming (continuous ingestion from Kafka/Kinesis)

Raw landing zone: [Where raw data lands before transformation — e.g. raw.salesforce_opportunities in Snowflake, S3 bucket s3://data-raw/crm/]

Schema handling: [Strict schema enforcement / Schema evolution allowed / Union schema]

4. Transformation Logic

List each transformation in execution order. For ELT pipelines, this is the dbt model or SQL layer.

Business logic rules:

• [e.g. Revenue is recognised on payment_confirmed_at, not payment_initiated_at]
• [e.g. Users in the internal@company.com domain are excluded from all metrics]
• [e.g. Currency conversion uses the ECB rate from the first business day of each month]

Slowly Changing Dimensions (SCD) — if applicable:

• [e.g. users.plan_tier is SCD Type 2 — keep history of plan changes with valid_from / valid_to]

5. Destination

Partitioning / Clustering: [e.g. Partitioned by event_date, clustered by user_id — reduces query cost for time-range scans]

Retention policy: [e.g. Raw data retained for 90 days; mart tables retained indefinitely]

6. Scheduling & SLAs

Schedule: [Cron expression and human description — e.g. 0 6 * * * — daily at 06:00 UTC]

Trigger type:

• Time-based (cron)
• Event-based (triggered by upstream pipeline success / file arrival / Kafka lag)
• Manual (ad hoc runs only)

Backfill strategy: [How to reprocess historical data if the pipeline fails or logic changes — e.g. parameterised date range, full drop-and-reload]

7. Data Quality Rules

DQ tool: [dbt tests / Great Expectations / Monte Carlo / custom SQL assertions]

8. Error Handling & Recovery

Retry policy: [e.g. 3 retries with exponential back-off: 5 min, 20 min, 60 min]

Failure modes and responses:

Dead-letter queue: [Where failed records are routed for manual inspection — e.g. raw.dlq_events]

9. Monitoring & Observability

Metrics to track:

• Pipeline run duration (p50, p95)
• Rows processed per run
• DQ check pass rate
• Source freshness lag
• Error rate per source

Alerting:

• [Slack channel: #data-alerts]
• [PagerDuty: data-on-call escalation for P1 SLA breaches]
• [Dashboard: [link to monitoring dashboard]]

Logging: [What gets logged and where — e.g. Airflow task logs to CloudWatch, structured JSON to data lake]

10. Dependencies & Sequencing

Upstream dependencies: [Which pipelines or data sources must succeed before this pipeline runs?]

Downstream dependents: [Which dashboards, pipelines, or models depend on this pipeline's output?]

[upstream pipeline A] ──► THIS PIPELINE ──► [downstream dashboard B]
                                          └──► [downstream pipeline C]

Coordination mechanism: [Airflow DAG dependency / dbt ref() / event trigger / manual gate]

11. Security & Compliance

• PII fields: [List columns containing PII — e.g. email, ip_address, name]
• Masking / Pseudonymisation: [e.g. email hashed with SHA-256 before landing in mart layer]
• Access control: [Who can query the destination tables? — e.g. Role-based access in Snowflake]
• Data residency: [Which regions is data permitted to transit and rest in?]
• Audit trail: [Is pipeline execution auditable for compliance purposes? Where are logs retained?]

Quality Checks

• Every source has an incremental key or full-refresh justification
• Business logic rules are documented, not just the SQL
• SLAs are agreed with consumers, not set unilaterally by engineering
• DQ checks cover completeness, uniqueness, freshness, and volume
• Failure modes include a documented recovery owner
• PII fields are identified and a treatment plan is specified

Anti-Patterns

• Do not spec a pipeline without defining SLAs — "as fast as possible" is not an acceptable freshness target
• Do not omit error handling and dead-letter queue strategy — every pipeline must specify what happens to failed records
• Do not design idempotent loads without documenting the deduplication key — assume reruns will happen
• Do not leave data quality rules implicit — schema validation, null checks, and referential integrity must be explicit
• Do not ignore schema evolution — specify how upstream schema changes are detected and handled

Example Trigger Phrases

• "Design a data pipeline for our Salesforce to Snowflake sync"
• "Write a pipeline spec for ingesting Stripe events into our data warehouse"
• "Build an ETL spec for our user activity data"
• "Document our dbt pipeline from raw events to the analytics mart"
• "Spec out the pipeline that feeds the executive dashboard"