Becoming a maintainer#

We value long-term contributors who demonstrate commitment, technical expertise, and community leadership. Becoming a maintainer is a natural progression for contributors who have shown consistent dedication to the project. This section outlines the pathway from contributor to maintainer, inspired by successful open-source projects like Xarray.

What is a Maintainer?#

Maintainers are trusted community members who have demonstrated deep commitment to the project and have been granted elevated permissions on the repository. They play a crucial role in:

  • Reviewing and merging pull requests

  • Managing releases and versioning

  • Setting technical direction and architecture decisions

  • Ensuring code quality and consistency

  • Mentoring new contributors

  • Representing the project in the community

For more details about maintainer responsibilities, see the Governance documentation.

The Path to Maintainership#

Becoming a maintainer is not about a specific number of contributions or a fixed timeline. Instead, it’s about demonstrating consistent commitment, technical competence, and alignment with the project’s values and goals. The path typically follows these stages:

The following flowchart illustrates the journey from contributor to maintainer:

        flowchart TD
    Start([New Contributor]) --> Stage1[Stage 1: Active Contributor<br/>3-6 months]
    
    Stage1 --> Contrib1[Regular contributions]
    Stage1 --> Standards[Follow standards]
    Stage1 --> Community[Community engagement]
    
    Contrib1 --> Check1{Quality and<br/>consistency?}
    Standards --> Check1
    Community --> Check1
    
    Check1 -->|Yes| Stage2[Stage 2: Trusted Contributor<br/>6-12 months]
    Check1 -->|No| Stage1
    
    Stage2 --> Review[Code review]
    Stage2 --> Mentor[Mentoring]
    Stage2 --> Complex[Complex issues]
    Stage2 --> Tier12[Tier 1-2 contributions]
    
    Review --> Check2{Leadership and<br/>expertise?}
    Mentor --> Check2
    Complex --> Check2
    Tier12 --> Check2
    
    Check2 -->|Yes| Stage3[Stage 3: Maintainer Candidate]
    Check2 -->|No| Stage2
    
    Stage3 --> Express[Express interest]
    Express --> Eval[Evaluation by maintainers]
    Eval --> Discuss[Internal discussion]
    Discuss --> Nominate{Nomination?}
    
    Nominate -->|Yes| Approve[Steering Council approval]
    Nominate -->|No| Stage2
    
    Approve --> Maintainer([Maintainer])
    
    classDef defaultStyle fill:#f5f5f5,stroke:#9e9e9e,stroke-width:2px,color:#333
    class Start,Stage1,Stage2,Stage3,Maintainer,Contrib1,Standards,Community,Check1,Review,Mentor,Complex,Tier12,Check2,Express,Eval,Discuss,Nominate,Approve defaultStyle
    
    style Start fill:#f5f5f5,stroke:#9e9e9e,stroke-width:2px
    style Stage1 fill:#e1bee7,stroke:#e1bee7,stroke-width:2px
    style Stage2 fill:#a3d8b0,stroke:#a3d8b0,stroke-width:2px
    style Stage3 fill:#e1bee7,stroke:#e1bee7,stroke-width:2px
    style Maintainer fill:#a3d8b0,stroke:#a3d8b0,stroke-width:3px
    style Check1 fill:#f5f5f5,stroke:#9e9e9e,stroke-width:2px
    style Check2 fill:#f5f5f5,stroke:#9e9e9e,stroke-width:2px
    style Nominate fill:#f5f5f5,stroke:#9e9e9e,stroke-width:2px

The following table compares the different stages:

Criterion

Stage 1: Active Contributor

Stage 2: Trusted Contributor

Stage 3: Maintainer Candidate

Typical duration

3-6 months

6-12 months

2-4 weeks (process)

Contributions

Regular and quality

Complex and significant

Leadership and responsibilities

Code review

Submit PRs

Review others’ PRs

Advanced review and mentoring

Engagement

Discussions and questions

Mentoring and triage

Project management

Validation

Mainly Tier 0

Tier 1-2 with validation

All tiers

Permissions

Standard contributor

Trusted contributor

Maintainer candidate

Next step

Stage 2

Stage 3

Maintainer

Stage 1: Active Contributor#

Focus: Build a track record of quality contributions

What to do:

  • Make regular, meaningful contributions (code, documentation, tests, reviews)

  • Follow all contribution guidelines and coding standards

  • Respond promptly to review feedback

  • Help improve documentation and examples

  • Participate in discussions and answer questions

What we look for:

  • Consistent contributions over time (not just one large contribution)

  • High-quality code that follows our standards

  • Good understanding of the codebase and project goals

  • Positive interactions with the community

Timeline: This stage typically lasts 3-6 months of active contribution, but can vary based on the nature and quality of contributions.

Stage 2: Trusted Contributor#

Focus: Demonstrate leadership and deeper engagement

What to do:

  • Take ownership of complex issues and features

  • Help review pull requests from other contributors

  • Mentor new contributors and answer questions

  • Propose and implement significant improvements

  • Participate actively in technical discussions

  • Help triage issues and improve project organization

  • Contribute to Tier 1-2 changes with scientific validation

What we look for:

  • Ability to review code effectively and provide constructive feedback

  • Leadership in technical discussions and decision-making

  • Mentoring and community-building skills

  • Deep understanding of the project’s scientific and technical aspects

  • Reliability and consistency in contributions

Timeline: This stage typically lasts 6-12 months, during which you build trust and demonstrate your commitment.

Stage 3: Maintainer Candidate#

Focus: Express interest and demonstrate readiness

What to do:

  • Continue all activities from Stage 2

  • Express interest in becoming a maintainer to current maintainers or the Open Science Lead

  • Take on additional responsibilities when asked

  • Help with release management and project maintenance tasks

  • Participate in maintainer discussions (as invited)

What we look for:

  • Proven track record of quality contributions and reviews

  • Strong alignment with project values and goals

  • Ability to work independently and make sound technical decisions

  • Excellent communication and collaboration skills

  • Commitment to the project’s long-term success

Process:

  1. Expression of Interest: You can express interest directly to current maintainers, the Open Science Lead, or by opening a thread in the Governance category on GitHub Discussions

  2. Evaluation: Current maintainers will review your contributions, community engagement, and technical expertise

  3. Discussion: Maintainers will discuss your candidacy internally

  4. Nomination: If there’s consensus, a maintainer will nominate you

  5. Approval: The nomination is reviewed by the repository stewards and ESA representatives

  6. Onboarding: Once approved, you’ll receive maintainer permissions and onboarding support

Timeline: The evaluation and approval process typically takes 2-4 weeks after expression of interest.

Key Qualities We Value#

While there’s no strict checklist, successful maintainers typically demonstrate:

Technical Excellence:

  • Deep understanding of the codebase and architecture

  • Strong software engineering skills

  • Knowledge of Earth observation and SAR processing (for scientific aspects)

  • Ability to write clear, maintainable code

  • Understanding of testing, validation, and quality assurance

Community Leadership:

  • Positive, respectful communication

  • Ability to mentor and guide others

  • Constructive feedback and code review skills

  • Conflict resolution abilities

  • Commitment to inclusivity and diversity

Project Commitment:

  • Long-term dedication to the project

  • Availability for reviews and maintenance tasks

  • Alignment with project goals and values

  • Understanding of governance and decision-making processes

  • Willingness to take on responsibilities

Scientific Rigor (for scientific aspects):

  • Understanding of validation requirements

  • Ability to review scientific changes

  • Knowledge of reference datasets and validation methods

  • Commitment to reproducibility and transparency

Maintainer Responsibilities#

Once you become a maintainer, you’ll take on additional responsibilities:

Code Review and Merging:

  • Review pull requests across all tiers

  • Ensure code quality and standards compliance

  • Approve and merge PRs after all requirements are met

  • Help resolve conflicts and technical issues

Project Maintenance:

  • Manage releases and versioning

  • Maintain code quality and architecture consistency

  • Respond to critical issues and security vulnerabilities

  • Manage protected branches and repository settings

Community Leadership:

  • Mentor new contributors

  • Participate in technical and governance meetings

  • Represent the project in the community

  • Help set technical direction and priorities

Governance:

  • Participate in maintainer discussions and decisions

  • Contribute to governance and policy discussions

  • Help ensure compliance with ESA policies and Open Science principles

How to Get Started#

If you’re interested in becoming a maintainer:

  1. Start Contributing: Focus on making quality contributions and building your track record

  2. Engage with the Community: Participate in discussions, help others, and build relationships

  3. Take on Challenges: Volunteer for complex issues and significant features

  4. Review Code: Start reviewing other contributors’ pull requests

  5. Express Interest: When you feel ready, express your interest to current maintainers

Remember: There’s no rush. Focus on making quality contributions and building trust with the community. Maintainership will come naturally as you demonstrate your commitment and capabilities.

Questions?#

If you have questions about the maintainer path or want to discuss your journey:

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