Airflow vs Dagster vs Prefect: Choosing the Right Data Orchestrator

Galaxy Glossary

How do Airflow, Dagster, and Prefect compare for data orchestration?

A practical comparison of Apache Airflow, Dagster, and Prefect—three leading open-source data workflow orchestrators—covering architecture, usability, reliability, and ecosystem fit.

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Description

Picking an orchestration framework can define your data platform’s reliability, developer experience, and long-term agility.

This guide dives deep into Apache Airflow, Dagster, and Prefect—highlighting where each shines, trade-offs to consider, and how to choose the best match for your team.

Why Orchestration Matters

Modern data pipelines stitch together extraction, transformation, machine-learning, and reporting tasks that span clouds, databases, and compute engines. An orchestrator coordinates those tasks, manages retries, records lineage, and alerts on failure—turning scripts into production-grade workflows. Selecting the wrong tool can produce cascading outages and frustrated engineers; choosing the right one accelerates iteration and trust in data.

Quick Definitions

  • Apache Airflow: The de-facto standard since 2015. DAG-based scheduler with a pluggable operator ecosystem and a rich UI for monitoring.
  • Dagster: A newer orchestrator focused on type-checked, testable pipelines, asset-based lineage, and a modern developer toolbox.
  • Prefect: A Pythonic framework that decouples orchestration (Prefect Cloud/Core) from execution and emphasizes observability and flexible deployment.

Architectural Overview

Airflow

Uses a centralized scheduler, metadata database (often Postgres/MySQL), and distributed workers (Celery, Kubernetes, or LocalExecutor). DAGs are parsed continuously from Python files mounted on every worker. UI, scheduler, and workers can scale independently but share the metadata store.

Dagster

Separates the Dagster Daemon (schedulers/sensors) and user code deployments. Assets and jobs are defined in Python modules, packaged as gRPC servers, and loaded into the Dagster web UI (Dagit). Strong typing and @asset abstractions build lineage graphs automatically.

Prefect

Defines Flows and Tasks in Python. Orchestration happens in Prefect Cloud (SaaS) or Prefect Server (OSS). Agents poll for work and execute flows in any environment—local process, Docker, Kubernetes, ECS—without the scheduler needing network ingress.

Developer Experience

  • Airflow: Declarative DAGs but imperative task bodies. Macros, Jinja templates, and XComs for data passing. Learning curve can be steep.
  • Dagster: Python functions with first-class type hints, asset materializations, and a pytest-friendly API. Dagit provides test runs and time-travel.
  • Prefect: Pure-Python tasks with .map() for dynamic workflows, parameterization via context, and a minimal decorator syntax. Real-time logs stream to the UI.

Reliability & Observability

Airflow relies on Scheduler heartbeats and a metadata DB; monitoring requires external tools like Prometheus or StatsD. Dagster captures structured metadata, versioned assets, and rich event logs out of the box. Prefect streams task states to Cloud with automatic retry rules, circuit-breaker patterns, and SLA alerts.

Ecosystem & Integrations

  • Airflow boasts 2000+ community operators (Snowflake, BigQuery, Databricks, etc.) and is battle-tested by Airbnb, Stripe, and DoorDash.
  • Dagster offers integrations through software-defined assets (SDAs) and libraries like dagster-snowflake and dagster-dbt. Community is growing fast.
  • Prefect integrates with dbt, Great Expectations, and Kubernetes. The distributed agent model suits hybrid/on-prem deployments.

Performance & Scaling

Airflow’s CeleryExecutor can scale horizontally but struggles with high DAG-parse times. Dagster’s gRPC user-code process isolates dependency trees, reducing scheduler load. Prefect’s agent model scales elastically—each flow run is just another container or process.

Cost Considerations

  • Airflow: Fully open-source, but operational overhead (database, queues, workers) accrues DevOps cost. Managed options exist (MWAA, Astronomer, Google Cloud).
  • Dagster: OSS core; Dagster Cloud offers hybrid and serverless tiers priced per compute hour & asset run.
  • Prefect: OSS server is free; Cloud’s usage-based pricing (task-run credits) aligns with scale.

Typical Use Cases

Airflow

Mature companies with heterogeneous workloads (batch Spark, Fivetran triggers, ML retraining) and strict change-management policies.

Dagster

Data-first teams prioritizing lineage, tests, and modular asset graphs—especially heavy dbt users seeking stronger orchestration than dbt run alone.

Prefect

Startups that need rapid iteration, hybrid/on-prem clusters, or want to adopt orchestration without maintaining stateful services.

Galaxy Connection

While Galaxy focuses on writing and sharing SQL, orchestrators schedule those SQL scripts in production. For example, an Airflow DAG may call a Galaxy-authored query stored in Git; a Dagster asset may materialize a table via Galaxy-generated SQL; Prefect flows can invoke Galaxy’s API to execute parameterized queries on demand. Galaxy doesn’t replace orchestration but makes the SQL tasks inside them more reliable and collaborative.

Best Practices for Selecting a Framework

  • Audit team skill sets—Airflow knowledge may exist already.
  • Map critical requirements: asset lineage? hybrid execution? SaaS compliance?
  • Pilot with a representative pipeline and measure developer onboarding time, deployment friction, and run stability.
  • Design for infrastructure as code (Terraform, Helm) regardless of choice.

Common Misconceptions

"Airflow is outdated."

Although older, Airflow 2.x introduced Smart Sensors, DAG versioning, and a performant scheduler—still evolving rapidly.

"Dagster is only for tiny teams."

Large enterprises (e.g., Voltron Data) run thousands of daily assets with Dagster Cloud; its asset graph scales horizontally.

"Prefect Cloud means vendor lock-in."

Flows remain pure Python and can target OSS server or Cloud interchangeably, mitigating lock-in risk.

Conclusion

No single orchestrator rules them all. Airflow provides breadth and stability, Dagster offers modern software-engineering rigor, and Prefect delivers flexibility with minimal ops. Evaluate culture, compliance, and data-product roadmap before adopting; switching later is costly.

Why Airflow vs Dagster vs Prefect: Choosing the Right Data Orchestrator is important

The orchestrator underpins every data product your organization ships—choosing the wrong one can cause cascading failures, hinder collaboration, and slow feature delivery. Understanding the strengths and trade-offs of Airflow, Dagster, and Prefect enables data engineers to select tooling that fits their team’s skills, compliance needs, and growth trajectory.

Airflow vs Dagster vs Prefect: Choosing the Right Data Orchestrator Example Usage


Compare orchestration tools: Is Dagster better than Airflow for dbt asset lineage?

Common Mistakes

Frequently Asked Questions (FAQs)

Is Airflow still the industry standard?

Yes, Airflow remains dominant due to its maturity and operator ecosystem. However, newer tools offer improved DX and reliability for certain workloads.

Can Dagster orchestrate non-Python jobs like Spark?

Absolutely. Dagster can invoke shell commands, Spark clusters, or dbt runs—the asset abstraction is language-agnostic.

How does Prefect handle dynamic workflows?

Prefect’s map() function and task loops let you generate tasks at runtime without pre-declaring the full graph.

Does Galaxy replace Airflow, Dagster, or Prefect?

No. Galaxy is a SQL editor and collaboration layer. You can embed Galaxy-created SQL inside tasks managed by any orchestrator.

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