sktime is a consensus-based community project. Anyone with an interest in the project can join the community, contribute to the project, and participate in the governance process. This document describes how that participation takes place, which roles we have in our community, how we make decisions, and how we acknowledge contributions.

We are particularly motivated to support new and/or anxious contributors, people who are looking to learn and develop their skills, and members of groups underrepresented in the tech sector. Go to our contributing guide for more details.



Code of Conduct

How we expect all members of the sktime community to interact


What roles we have in sktime’s community and what rights and responsibilities they have

Decision making

How and by whom decisions are made

Acknowledging contributions

How we acknowledge contributions


What we may change in the future

Code of Conduct#

We value the participation of every member of our community and want to ensure an that every contributor has an enjoyable and fulfilling experience. Accordingly, everyone who participates in the sktime project is expected to show respect and courtesy to other community members at all times.

We ask all members of the community to conform to our Code of Conduct.


We distinguish between the following key roles that community members may exercise. For each role, we describe their rights and responsibilities, and appointment process in more detail below.






Concrete contribution

Algorithm maintainers

Algorithm maintenance, voting and veto right for changes to their algorithm

Algorithm contribution or appointment by current maintainer

Core developers

Direct write access, issue/PR management, veto right, voting, nomination

Nomination by core developers, vote by core developers, 2/3 majority

CoC committee members

CoC maintenance, investigation and enforcement

Nomination by core developers, vote by core developers, 2/3 majority and simple CoC majority

CC members

Conflict resolution, technical leadership, project management

Nomination by core developers, vote by core developers, 2/3 majority and simple CC majority

CC observers

Full view of CC communication, direct input on CC decisions

Nomination by core developers, vote by CC members, simple CC majority


Contributors are community members who have contributed in concrete ways to the project. Anyone can become a contributor, and contributions can take many forms – not only code – as detailed in the contributing guide.

For more details on how we acknowledge contributions, see Acknowledging contributions below.

All contributors are listed in

Algorithm maintainers#

Algorithm maintainers are contributors who have contributed an algorithm. They have the same voting rights as core developers with regard to their algorithm.

In sktime, algorithms are encapsulated in classes with specific interface requirements and are called estimators. To facilitate maintainership questions, we try to write algorithms in separate files when possible.

To clarify, “algorithm” in the above sense means “implemented estimator class”. That is, algorithm maintainers gain rights and responsibilities with respect to that python code. They do not gain any rights on abstract methodology, e.g., in a case where the class implements methodology invented by third parties.

In particular, algorithm maintainers do not gain rights or responsibilities on other, potential implementations of the same methodology in their estimator class.

Rights and responsibilities#



Decision making with respect to their algorithm

Algorithm maintainers can partipate in the decision making process by vetoing changes and casting votes with regard to proposed changes to their algorithm. This does not extend to proposed changes to the common framework and API.


They are responsible for maintaining the code and documentation for their algorithm, including bug fixes, unit testing, coding style, compliance with the common API, docstrings, documentation and tutorials notebooks.


They are the first point of contact for users and other contributors for all questions, issues and proposals regarding their algorithm.

Recall, “algorithm” refers to estimator classes.

Therefore, the above rights and responsibilities exclude any power on further, potential implementations of the same or similar methodology.

For instance, an algorithm maintainer of algorithm A implemented in class X cannot prohibit implementation of algorithm A in class Y. They can only make decisions about changes on class X. Class Y can be owned by a different algorithm maintainer.

In particular, there can be multiple classes implementing algorithm A, and the algorithm maintainer of class X cannot prohibit implementation of, or make decisions on class Y.


Without restriction to eligibility, it is generally expected that algorithm maintainers have a very good technical and methodological understanding of the algorithm they maintain.

This understanding is typically present in inventors or proponents of said algorithm, but it is not necessary to be the inventor of an algorithm to be its maintainer.


Anyone is eligible to be an algorithm maintainer.

Anyone is eligible to be an algorithm maintainer of a specific algorithm that does not already have an algorithm maintainer.

The presence of a specific implementation of a given abstract algorithm does not prevent anyone from becoming the algorithm maintainer of a different implementation of the same (or similar) abstract algorithm.


The contributor who contributes an algorithm is automatically appointed as its first maintainer.

Algorithm maintainers are listed in the "maintainers" tag of the estimator class, by their GitHub ID. The GitHub ID can be linked to further information via the all-contributorsrc file. The tag can be inspected directly in the source code of the class, or via EstimatorName.get_class_tag("maintainers"). Inverse lookup such as “which algorithms does maintainer M maintain” can be carried out using registry.all_estimators.

When an algorithm maintainer resigns, they can appoint another contributor as the new algorithm maintainer. No vote is required. This change should be reflected in the "maintainers" tag.

Algorithm maintainers can be appointed by CC simple majority for any algorithm without maintainers.

End of tenure#

If algorithm maintainers can no longer fulfil their maintenance responsibilities, maintainers are expected to resign.

Algorithm maintainers that have been unresponsive for a 3 month period automatically give up their rights and responsibilities as algorithm maintainers.

Unresponsiveness is defined as: * not engaging with decision making procedures within the reasonably time frames defined there * not reacting to issues or bug reports related to the algorithm, within ten working days

Core developers#

Core developers are contributors who have shown that they are dedicated to the continued development of the project through ongoing engagement with the community.

Current core developers are listed in the core-developers team within the sktime organisation on GitHub.

Rights and responsibilities#



Direct access

Being a core developer allows contributors to more easily carry on with their project related activities by giving them direct access to the project’s repository.

Issue/PR management

Core developers are responsible for reviewing and managing issues and pull requests. This includes commenting on issues, reviewing code contributions, merging approved pull requests, and closing issues once resolved.

Decision making

They can participate in the decision making process by vetoing changes and casting votes.


They can nominate new core developers, CoC committee members and CC members.


Anyone is eligible to be a core developer.


New core developers can be nominated by any current core developer. Once they have been nominated, there will be a vote by the current core developers.

Voting on appointments is one of the few activities that takes place on the project’s private communication channels. The vote will be anonymous.

While it is expected that most votes will be unanimous, a 2/3 majority of the cast votes is enough. The vote needs to be open for five days excluding weekends.

End of tenure#

Core developers can resign voluntarily at any point in time, by informing the CC in writing.

Core developers that have not contributed to the project in the past one-year-period will automatically become inactive and give up their rights and responsibilities. When they become active again, they can retake their role without having to be appointed.

Becoming inactive in the above sense means not contributing for the period via:

  • creating pull requests

  • commenting on pull requests or issues

  • attending one of the regular meetings

Becoming active (after becoming inactive) in the above sense requires one of:

  • an approved pull request authored by the core developer

  • a contribution to the community that is minuted in one of the regular meetings

CoC committee members#

CoC members are contributors with special rights and responsibilities. The current members of the CoC committee are listed in the CoC.

Rights and responsibilities#

CoC committee members are responsible for investigating potential CoC incidents and enforcing the CoC. They are the point of contact for reporting potential CoC incidents.

In addition, they are responsible for maintaining and improving the CoC.


Anyone is eligible to be a CoC committee member.


Membership of the CoC is by nomination by a core developer and a vote by all core developers. A nomination will result in discussion which will stay open for 5 days excluding weekends and then a vote by the core developers which will stay open for 5 days excluding weekends. CoC committee membership votes are subject to:

  • a 2/3 majority of all cast votes, and

  • a simple majority approval of all the current CoC committee members.

The vote will take place in private communication channels and will be anonymous.

To avoid deadlocks if there is an even number of CoC committee members, one of them will have a tie breaking privilege.

CC members#

CC (community council) members are core developers with additional rights and responsibilities to avoid deadlocks and ensure a smooth progress of the project.

Current CC members are listed in the community-council team within the sktime organisation on GitHub.

Rights and responsibilities#



Decision making: conflict resolution

see Stage 3: conflict resolution below

Technical direction

Strategic planning, development roadmap

Project management

Funding, collaborations with external organisations, community infrastructure (chat server, GitHub repositories, continuous integration accounts, social media accounts)


Only core developers are eligible for appointment as CC members. Non-core-developers can be nominated, but this must be accompanied by a nomination for core developer, and a core developer appointment vote concurrent with the 5 day discussion period (see below).


Appointment to the CC is by nomination by a core developer and a vote by all core developers. A nomination will result in discussion which stays open for 5 days excluding weekends and then a vote by core developers which will stay open for 5 days excluding weekends. Approval of appointment requires:

  • a 2/3 majority of all cast votes, and

  • a simple majority approval of all the current CC members.

The core developer vote takes place in private communication channels, visible to, and only to, core developers, and is anonymous. The CC members’ vote takes place in private communication channels, visible to, and only to, CC members, and is anonymous.

In case the CC members’ vote is tied, the CC member with the shortest continuous tenure has a tie breaking privilege.

The tie breaking is by construction visible to CC members, does not require the tie breaking CC member to have voted in the anonymous vote, and need not follow their anonymous vote if they have voted.

End of tenure#

CC members can resign voluntarily at any point in time, by informing the CC in writing.

CC members who do not actively engage with their CC member role responsibilities are expected to resign voluntarily.

Tenure also ends automatically when a CC member’s tenure as core developer ends, e.g., through resignation or inactivity.


The CC has regular public meetings that the full community is welcome to attend.

For more details about our meetings, please go to our community-council repository.

To contact the CC directly, please send an email to

CC observers#

CC (community council) observers are core developers with additional rights and responsibilities. Current CC observers are listed in the community-council observers .

Rights and responsibilities#

CC observers have a full view of reserved CC proceedings, the private CC channels and the sktime email account. CC observers can participate in discussions on private CC channels to ensure that more members of the community have direct input on CC decisions.

CC observers’ responsibilities include to critically scrutinize CC decision making and give their input on what is of community’s interest or benefit.

CC observers do not possess the voting or decision making rights of full CC members.


Only core developers are eligible for appointment as CC observers. Non-core-developers can be nominated, but this must be accompanied by a nomination for core developer, and a core developer appointment vote (see below).


Membership of the CC observers is by nomination by a core developer and a vote by CC members. A nomination will result in a vote by the CC members which will stay open for 5 days excluding weekends. CC observer membership votes are subject to a simple majority approval of all the current CC committee members.

In case of ties, the CC member with shortest tenure breaks the tie.

Special operational role: treasurer#

The treasurer is an appointed role on the sktime project. This is primarily a supportive and transparency enhancing role.

If the treasurer role remains unfilled for longer than a month, the CC must exercise the responsibilities of the treasurer role, as a committee.

Rights and responsibilities#

The treasurer will work closely with the CC to set financial goals, allocate resources, and ensure ethical fiscal management.

Responsibilities include budgeting, fiscal management, financial reporting, internal policy compliance, and cash management.

The treasurer’s primary responsibility is to produce the financial statements and budgets for the project in a timely manner.

Eligibility and appointment#

The treasurer role is open to core developers of the sktime project.

Non-core developers must be confirmed as core developers before being considered for the treasurer role.

The CC appoints the treasurer through majority vote, among suitable candidates for the role.

The CC should solicit nominations from the community in transparent communication channels, when the role needs to be filled.

Tenure and removal#

The treasurer serves a one-year term with the possibility of re-appointment.

Inactivity may result in removal if the treasurer fails to compile budgets or financial statements as required.

Removal for code of conduct violations related to fiscal transparency requires a CoC investigation.

Decision making#

The purpose of this section is to formalize the decision-making process used by the sktime project. We clarify:

  • what types of changes we make decision on,

  • how decisions are made, and

  • who participates in the decision making.

sktime’s decision-making process is designed to take into account feedback from all community members and strives to find consensus, while avoiding deadlocks when no consensus can be found.

All discussion and votes takes place on the project’s issue tracker, pull requests or an sktime enhancement proposal. Some sensitive discussions and appointment votes occur on private chats.

The CC reserves the right to overrule decisions.

We distinguish between the following types of proposed changes. The corresponding decision making process is described in more detail below.

Type of change

Decision making process

Code additions, such as new algorithms

Lazy consensus, supported by the Algorithm inclusion guidelines

Minor documentation changes, such as typo fixes, or addition/correction of a sentence

Lazy consensus

Code changes and major documentation changes

Lazy consensus

Changes to the API design, hard dependencies, or supported versions

Lazy consensus, requires a sktime enhancement proposal

Changes to sktime’s governance (this document and the CoC)

Lazy consensus, requires a sktime enhancement proposal


Directly starts with voting (stage 2)

Stage 1: lazy consensus with veto right#

sktime uses a “consensus seeking” process for making decisions. The community tries to find a resolution that has no open objections among core developers.

  • Proposed changes should be in the form of GitHub pull requests (PR). Some changes also require a worked out sktime enhancement proposal. This depends on the type of change, see decision making process above.

  • For a proposed change to be approved via lazy consensus, it needs to approval by at least one core developer (lazy consensus) and no rejection by a core developer (veto right). The approval required for this condition must be by a core developer different from a proposer.

  • For a proposed change to be rejected via lazy consensus, it needs to receive a rejection by at least one core developer, and no acceptance by a core developer.

  • Approvals must be in the form of a GitHub PR approval of the PR in question. Rejections can be expressed as -1 comments, or any written comments containing “I formally reject” in the PR, in reference to it.

  • Proposers are expected to give reasonable time for consideration, that is, time and opportunity for core developers to review and give their opinion on the PR. Ten working days excluding week-ends constitute “reasonable time” in the above sense. The period resets at every new change made to the PR. It starts only when all GitHub checks pass.

  • During this period, the PR can be merged if it has an approval and no rejection, but should be reverted if it receives a rejection in addition.

  • If the “reasonable time” period elapses and no approval or rejection has been expressed on a PR, the PR is scheduled at the top of agenda for the next developer meetup. In that meeting, a core developer is assigned to review the PR and either approve or reject within five days of the meeting excluding weekends.

Failure of lazy consensus, in the above sense, can arise only under the following condition: at least one approval and at least one rejection in the PR.

When no consensus can be found, the decision is escaled to Stage 2: voting.

Stage 2: voting#

Voting takes place:

  • when no lazy consensus can be found in stage 1 above

  • for appointments

  • The start of a voting period after stage 1 is at the moment the lazy consensus fails.

  • Start and end time of the vote must be announced in the core developer channel, and on the PR (if on a PR).

  • The vote will conclude 5 days excluding weekends from the call for the vote.

  • Votes are voluntary. Abstentions are allowed. Core developers can abstain by simply not casting a vote.

  • All votes are a binary vote: for or against accepting the proposal.

  • Votes are casts as comments: +1 (approval) or -1 (rejection).

For all types of changes, except appointments, votes take place on the related public issue or pull request. The winning condition is a 2/3 majority of the votes cast by core developers (including CC members) for the proposal. If the proposal cannot gather a 2/3 majority of the votes cast by core developers, the decision is escalated to the Stage 3: conflict resolution.

For appointments, votes take place in private communication channels and are anonymous. The winning conditions vary depending on the role as described in Roles above. Appointment decisions are not escalated to the CC. If a nomination cannot gather sufficient support, the nomination is rejected.

Stage 3: conflict resolution#

If the proposed change cannot gather a 2/3 majority of the votes cast, the CC tries to resolve the deadlock.

  • The CC will use consensus seeking.

  • If no consensus can be found within twenty working days excluding weekends since the beginning of the stage-1 “reasonable time for consideration” period, the decision is made through a simple majority vote (with tie breaking) among the CC members.

  • Any proposal reaching stage 3 must be supported by an sktime enhancement proposal, which has been made public at least 5 days, excluding weekends, before the vote.

sktime enhancement proposal#

sktime enhancement proposals (STEPs) are required for:

  • certain types of proposed changes, by default, see decision making process

  • for all stage 3 decisions

If a STEP is required by a vote, it must have been made public at least 5 working days (excluding week-ends) before that vote.

A STEP is a consolidated document, with a concise problem statement, a clear description of the proposed solution and a comparison with alternative solutions, as outlined in our template.

A complete STEP must always include at least a high-level design for the proposed change, not just a wishlist of features.

Usually, we collect and discuss proposals in sktime’s repository for enhancement-proposals.

For smaller changes, such as punctual changes to the API or governance documents, the STEP can also be be part of an issue or pull request.

Algorithm inclusion guidelines#

Curation is about how we select contributions, which criteria we use in order to decide which contributions to include, and in which cases we deprecate and remove contributions.

We have the following guidelines:

  • sktime aims to provide a repository for algorithms to enhance reproducible research, putting no lower bounds on number of citations, algorithmic performance, or frequency of use.

  • For inclusion, a scientific reference must be available and linked to the python estimator. A scientific reference is a formal description of the algorithm which satisfies basic scientific requirements, e.g., be formally correct, complete, and adhere with common conventions on presentation in the field of data science.

  • The scientific reference must be free from unfounded scientific claims, pseudo-science, commercial marketing, or other content inappropriate for a scientific reference. The scientific reference must adhere to proper scientific citation standards, i.e., citing primary sources, giving proper credit. The form of the scientific reference can be a description in the class docstring, or a link to a scientific document, e.g., on the arXiv. Such a scientific document need not be peer-reviewed or journal published, but must adhere to scientific standards.

  • We strive to consolidate existing functionality if it helps to improve the usability and maintainability of the project. For example, when there are multiple techniques for the same purpose, we may choose to present one variant as the “primary default”, and rarer variants as less accessible or findable alternatives. The choice of the “primary default” may change with use and relevance in the user community. We are aware that the choice of the “primary default” may give or remove visibility, and aim to make the choice for usability and quality of the selection.

  • We are happy to accept historical algorithms of interest, as references to use in reproduction studies, including historical versions that are faulty implementations. Algorithms of historical interest will be clearly labelled as such, and inclusion is primarily guided by relevance, e.g., as a reference in an important study, relevance in the scientific discourse, or as an important algorithmic baseline.

  • From the algorithms or techniques that meet the above criteria, only those which fit well within the current framework of sktime are accepted. For algorithms that do not fit well into one of the current API definitions, the API will have to be extended first. For extending current API, see the decision making process for major changes.

Note that an algorithm need not be in sktime to be fully compatible with sktime interfaces. You can implement your favorite algorithm in a sktime compatible way in a third party codebase - open or closed - following the guide for implementing compatible estimators (see developer_guide_add_estimators:).

We are happy to list any compatible open source project under related software. Contributions are also welcome to any one of our companion repositories on GitHub.

Dependencies are managed on the level of estimators, hence it is entirely possible to maintain an algorithm primarily in a third or second party package, and add a thin interface to sktime proper which has that package as a dependency.

Acknowledging contributions#

sktime is collaboratively developed by its diverse community of developers, users, educators, and other stakeholders. We value all kinds of contributions and are committed to recognising each of them fairly.

We follow the all-contributors specification to recognise all contributors, including those that don’t contribute code. Please see our list of all contributors.

If you think, we’ve missed anything, please let us know or open a PR with the appropriate changes to sktime/.all-contributorsrc.

Note that contributors do not own their contributions. sktime is an open-source project, and all code is contributed under our open-source license. All contributors acknowledge that they have all the rights to the code they contribute to make it available under this license.

The project belongs to the sktime community, and all parts of it are always considered “work in progress” so that they can evolve over time with newer contributions.


We are open to improvement suggestions for our governance model. Once the community grows more and sktime’s code base becomes more consolidated, we will consider the following changes:

  • Allow for more time to discuss changes, and more time to cast vote when no consensus can be found,

  • Require more positive votes (less lazy consensus) to accept changes during consensus seeking stage,

  • Reduce time for maintainers to reply to issues

In addition, we plan to add more roles for managing/coordinating specific project:

  • Community manager (mentorship, outreach, social media, etc),

  • Sub-councils for project-specific technical leadership (e.g. for documentation, learning tasks, continuous integration)


Our governance model is inspired by various existing governance structures. In particular, we’d like to acknowledge: