Astronomer

Best Self Hosted Alternatives to Astronomer

A curated collection of the 5 best self hosted alternatives to Astronomer.

Managed Apache Airflow platform for scheduling and orchestrating data workflows in the cloud. Provides hosted Airflow deployments, autoscaling, monitoring/observability, CI/CD for DAGs, multi-environment deployments, and governance for running ETL and data pipeline workloads.

Alternatives List

#1
Apache Airflow

Apache Airflow

Apache Airflow is a workflow orchestration platform to define, schedule, and monitor data pipelines and other batch jobs using Python-defined DAGs.

Apache Airflow screenshot

Apache Airflow is an open source platform for programmatically authoring, scheduling, and monitoring workflows. Workflows are defined as code (DAGs), making them maintainable, versionable, and easier to test and operate at scale.

Key Features

  • Define workflows in Python with dynamic DAG generation and parametrization
  • Scheduling and dependency management for complex task graphs
  • Scalable execution using a scheduler and distributed workers, typically backed by a message queue
  • Web UI to visualize DAGs, monitor runs, inspect logs, and troubleshoot failures
  • Extensible architecture with a large ecosystem of operators, hooks, and provider integrations
  • Templating support (Jinja) for runtime parameters and task configuration

Use Cases

  • Orchestrating ETL/ELT data pipelines and batch data processing
  • Running scheduled machine learning and analytics workflows
  • Coordinating infrastructure or application automation that requires dependency-aware execution

Limitations and Considerations

  • Best suited for mostly static, slowly changing workflow structures rather than highly dynamic per-run graphs
  • Not a streaming engine; common patterns process near-real-time data in batches
  • Tasks should be idempotent and should avoid passing large datasets between tasks (use external storage/services and pass metadata instead)

Apache Airflow is a strong fit when you need reliable, observable orchestration for batch workflows with clear dependencies and operational controls. Its extensibility and broad integration ecosystem make it adaptable across many data and automation environments.

43.9kstars
16.3kforks
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#2
Kestra

Kestra

Declarative, API-first orchestration platform for scheduled and event-driven workflows with a plugin ecosystem, UI editor, CI/CD and Terraform integration.

Kestra screenshot

Kestra is an open-source, event-driven orchestration platform for building, scheduling and operating workflows using a declarative YAML model. It provides an API-first experience and a web UI that keep workflows as code while enabling visual inspection, iterative testing and execution.

Key Features

  • Declarative YAML workflows with inputs, variables, subflows, conditional branching, retries, timeouts and backfills
  • Event-driven and scheduled triggers (webhooks, message buses, file events, CRON/advanced schedules) with millisecond latency support
  • Rich plugin ecosystem and task runners to run code in any language (Python, Node.js, R, Go, shell, custom containers) and connect to databases, cloud services and message brokers
  • Built-in web UI with code editor (syntax highlight, autocompletion, topology/DAG view), execution logs, dashboards and a Playground mode for iterative task testing
  • API-first design, Git/version-control integration and Terraform provider for Infrastructure-as-Code and CI/CD workflows
  • Scalable, fault-tolerant architecture with workers, executors and support for containerized and Kubernetes deployments

Use Cases

  • Data pipeline orchestration: scheduled ETL/ELT, batch and streaming data workflows, integration with databases and cloud storage
  • ML/AI and model pipelines: orchestrate preprocessing, training, validation and deployment steps across compute runners
  • Infrastructure and business automation: orchestrate provisioning, service orchestration, webhooks and event-driven automation across teams

Limitations and Considerations

  • Advanced governance features (SSO, RBAC, multi-tenant enterprise controls) are provided in commercial/Enterprise offerings rather than the core open-source distribution
  • Frontend editing capabilities (interactive drag-and-drop flow editing) are evolving; some UI graph editing features are currently limited and under active development
  • Plugin coverage varies by integration; teams building uncommon integrations may need to implement or maintain custom plugins

Kestra combines an Everything-as-Code approach with a feature-rich UI and extensible plugin model to unify orchestration across data, infra and application workflows. It is designed for teams that need both developer-grade reproducibility and operational observability in workflow automation.

26.2kstars
2.5kforks
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#3
Rundeck

Rundeck

Open-source runbook automation platform to schedule jobs, orchestrate workflows, and provide controlled self-service operations via web UI and API.

Rundeck screenshot

Rundeck is an open-source runbook automation and orchestration platform used to standardize and safely execute operational procedures across fleets of nodes. It provides a web console, CLI tools, and an API for running jobs, scheduling work, and delegating routine operations with controlled access.

Key Features

  • Runbook/job execution across nodes using existing scripts and automation tools
  • Workflow orchestration with step-based jobs and reusable procedures
  • Job scheduling for recurring operational tasks
  • Web UI, CLI, and REST API for triggering and managing automation
  • Access control and audit history for operational actions
  • Plugin ecosystem for integrations and extensibility

Use Cases

  • Self-service operations for DevOps/platform teams (safe execution of routine tasks)
  • Scheduled maintenance, batch operations, and runbook-driven incident response
  • Orchestrating deployments and administrative workflows across infrastructure

Limitations and Considerations

  • Some capabilities (for example advanced high availability and certain enterprise runners/plugins) may be available only in commercial editions.

Rundeck is well-suited for teams that want to operationalize scripts and tooling into repeatable runbooks with governance. It helps reduce manual toil by making operations workflows easy to run, schedule, and audit.

6kstars
966forks
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#4
Dagu

Dagu

Portable, file-backed workflow orchestrator that defines DAGs in declarative YAML, runs anywhere as a single binary, and includes a modern Web UI for monitoring and control.

Dagu screenshot

Dagu is a lightweight workflow orchestration engine that runs as a single self-contained binary and provides a modern Web UI. Workflows are defined in a declarative YAML format and can execute local commands, SSH commands, and containerized steps with scheduling and retries.

Key Features

  • Single-binary installation with zero required external dependencies; uses file-based storage for definitions, logs, and history
  • Declarative YAML DSL for DAGs with scheduling (cron), timezones, conditional steps, retries, and repeat policies
  • Built-in Web UI: visual DAG view, real-time monitoring, execution history, log search, and an integrated YAML editor
  • Executors for shell commands, Docker containers, SSH remote execution, and HTTP steps
  • Distributed execution: coordinator/worker model and built-in queueing to scale across machines
  • Nested/sub-DAG support for reusable composition and inspectable sub-runs in the UI
  • Integrations and platform features: GitHub Actions executor, API key management and RBAC, webhooks, email notifications
  • Newer features include human-in-the-loop approvals and a Chat Executor for integrating LLMs into workflows

Use Cases

  • Replace scattered cron jobs with a visual, auditable DAG system for server maintenance and operational scripts
  • Orchestrate multi-step CI/maintenance workflows that mix local scripts, SSH calls, and containerized tasks
  • Run distributed data-processing pipelines across multiple worker nodes with centralized monitoring and retries

Limitations and Considerations

  • Secrets management is not provided as a full built-in secret store; references and integrations (KMS/Vault/OIDC) are discussed/tracked as planned features
  • While Dagu supports distributed runs and queueing, very large cloud-native deployments may require external orchestration or custom scaling strategies

Dagu is designed for teams that want powerful orchestration with minimal operational overhead and straightforward local-first deployment. It emphasizes portability, simple YAML-based definitions, and an integrated UI for everyday workflow operations.

3kstars
223forks
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#5
CTFreak

CTFreak

On-premises IT task scheduler to centralize, schedule, and run scripts and commands across servers via SSH/WinRM, with workflows, logs, notifications, and an API.

CTFreak screenshot

CTFreak is an on-premises IT task scheduler designed to centralize scripts and operational jobs in one place, replacing scattered cron jobs and ad-hoc runbooks. It provides a fast, mobile-first web UI to execute tasks locally or remotely across heterogeneous environments.

Key Features

  • Remote executions on multiple nodes via SSH and WinRM, without installing agents
  • Task types for commands, Bash scripts, PowerShell scripts, Ansible playbooks, SQL scripts, and HTTP requests
  • Workflow engine to chain tasks sequentially or concurrently, including nested workflows
  • Team-based organization, centralized execution history, and consolidated logs
  • Notifications and alerting integrations (e.g., email, Slack, Microsoft Teams, Discord, Telegram, Mattermost)
  • Issue tracking integrations (e.g., GitHub, Jira, Linear, YouTrack)
  • SSO support via OpenID Connect
  • REST API plus incoming webhooks for automation and integrations
  • Lightweight resource usage and simple deployment

Use Cases

  • Sysadmin/DevOps job orchestration: maintenance, updates, and operational scripts across fleets
  • Data engineering operations: run long or concurrent imports and calculations on distributed servers
  • Self-service operations for business users: safely trigger pre-defined IT tasks via a web UI

Limitations and Considerations

  • Some advanced capabilities and higher limits (e.g., unlimited tasks, broader notifier quotas) depend on the chosen edition

CTFreak fits teams that want a straightforward, lightweight alternative to heavier runbook automation platforms while keeping strong visibility into job history and failures. It is especially useful in mixed Windows/Linux environments thanks to SSH and WinRM support.

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Why choose an open source alternative?

  • •Data ownership: Keep your data on your own servers
  • •No vendor lock-in: Freedom to switch or modify at any time
  • •Cost savings: Reduce or eliminate subscription fees
  • •Transparency: Audit the code and know exactly what's running