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September 15, 2021
Announcing FLIP Fest, the Flow Buildathon
Announcing FLIP Fest, the Flow Buildathon

The first ever Flow FLIP Fest is here; a buildathon for developers to collaborate on an open source blockchain project. A FLIP is a Flow Improvement Proposal; a community-driven initiative to discuss and execute impactful improvements on Flow.

The Flow FLIP Fest is a two-month event that will engage and reward participants for creating innovative and effective improvements to Flow. The goal of FLIP Fest is to empower developers to build solutions on Flow that will have a lasting impact on the developer community and broader consumer audience by extension. There are many areas to contribute, including: Non-custodial wallets, SDKs, learning tools, and more critical areas where participants will propose their solutions to specified needs. This also includes feature requests from businesses already developing on Flow.

FLIP Fest registration opens on Sept. 15, 2021, and has been extended to Oct. 22, with FLIP Fest ending on October 30.

FLIP Fest will be focused on the following themes: Wallets, SDKs, Local Development Tools, Non-Custodial Wallet Providers, and Learning Tools.

HackerEarth will host FLIP Fest, so head over there to register today and learn more about what participants can expect. There is no cost to register to participate, so if you’re ready to sign your team up to take on your next challenge, there’s no barrier for entry.

Sign Up: Apply here

Prize Pool: $500,000 in FLOW

Key Dates

  • Sept. 15: Registration opens
  • Oct. 22: Extended Registration ends
  • Oct. 30: FLIP Fest ends
  • Nov. 15: Winners announced

Best Solution Rewards

For teams that complete all the listed milestones for any project, they will be automatically considered for the best solution reward. This reward will be given to the team with best solution amongst any other team submissions that have also completed all milestones. All milestones must be completed and approved by October 15th, 2021 to be considered. The reward is based on the tier of the project that was being built. The winning team will also receive all 'Milestone Rewards' alongside this prize amount.

Best Solution - Per Tier 1 Issue: $50,000

Best Solution - Per Tier 2 Issue: $25,000

Best Solution - Per Tier 3 Issue: $5,000

*Note prizes will be distributed in FLOW token of equivalent USD value (we will use the daily average price for the month of Nov 2021 to calculate the conversion rate)

Prize Structure

FLIP Fest offers three tiers of projects to tackle, with Tier 1 being the most challenging and Tier 3 being the simplest. Each tier is split into milestones, which are checkpoints for the Flow team to: review your work, provide feedback, and give the final approval for completion. Select an appropriate tier of project for yourself based on your current skills and available time commitment.

Tier 1

  • A minimum of 4 milestones
  • Requires significant experience in a domain or language
  • May require sophisticated understanding of Flow, its ecosystem, and/or other accompanying tools.

Tier 2

  • 2-3 milestones
  • Requires some experience in a domain or language
  • May require some understanding of Flow, its ecosystem, and/or other accompanying tools.

Tier 3

  • Single milestone
  • May require knowledge of a specific language
  • Usually a self-isolated task with limited knowledge needed outside of the given repository.

Milestone Completion Rewards

For completing a milestone that meets the requirements set by the project and the respective point of contact (POC), your team will be rewarded with a base prize amount. This base prize amount applies for each milestone you complete. Based on the tier, your project may not have all four milestones.

Milestone 1: $250 USD

Milestone 2: $1000 USD

Milestone 3: $2500 USD

Milestone 4: $5000 USD

*Note prizes will be distributed in FLOW token of equivalent USD value (we will use the daily average price for the month of Nov 2021 to calculate the conversion rate)


Infrastructure Tools

Blockchain introduces new sets of use cases that need to be handled to bridge the gap between the chain and an application. This track contains building tools and services that will aid applications in managing their on-chain interactions.

Examples: Self-custody Wallets, Wallet APIs, Self-hosted Events Provider

Local Development Tools

Developers spend the majority of their time deep in the local tooling on Flow while building their applications. This stream of work involves making these development workflows easier, faster, and ultimately inspire developer confidence in their logic and code.

Examples: CLI, Emulator, Block Explorers, Testing frameworks


Flow is looking to expand the features of its current SDKs as well as introduce new SDKs for popular languages to grow the ecosystem. In this stream, you will be able to pick any of the existing libraries or create your own to bring it up to spec with our SDK guidelines and maintain it as Flow evolves.

Examples: Python, Ruby, C#, and more

Non-custodial Wallet Providers

The non-custodial ecosystem of wallets is what power the user to freely move between experiences on Flow with ease. In this track, we're welcoming any teams that would like to build an FCL compatible wallet that demonstrates excellent user experience and security for users to use in any application on Flow.

Learning Tools

Learning tools help reduce the complexity of onboarding onto Flow as a new developer. We're looking to expand our set of learning tools to cover a broader base of developers. This includes improving the experience on our playground as well as expanding our current examples to fit the needs of other developer communities.

Examples: Playground, Kitty-items

Getting Started 

Once you have registered on HackerEarth and found a team or chosen to work solo, go to the FLIP-Fest Github repository to find any issue(s) you would like to sign-up to work on. We also advise that you join our Flow Discord Server and check out the FLIP Fest Category to get announcements, connect with Flow core contributors and other participants. 

To work on an issue post the following as a comment on the issue on Github:

  • Your team name with a link to the HackerEarth team
  • Tag all team members with their Github usernames that are working on the project
  • When you plan on completing the first milestone.

If there are more than 5 teams that already expressed interest in working on a project (issue), we would highly suggest selecting another one from the issue list.

Please be aware that the point-of-contact (PoC) of the issue might reach out to you if there were any issues and you may be asked to delay your start and discuss details with the team privately if:

  • You or any member of your team is over-subscribed to too many projects and requires a discussion with the team
  • We suspect there may be a mismatch of the skills and experience required to finish the project adequately within the Oct 15th deadline.
  • We are requesting more details on the approach and/or implementation to remove redundancies across teams
  • If there are more than 5 teams that would like to work on a project, we may ask some teams to consider working together.

Once you have begun work, you should start to prepare for your first milestone submission. A milestone submission is a PR that should be directed at: '/submissions/issue-#/milestone-#/team-name' with the issue linked in the PR. See the sample PR for what to generally include in the submission.

After any submission, the Flow team will review PRs every week on Thursday and Friday to provide feedback and approvals. If your PR is merged, you will get the completion reward for the milestone and can move onto the next one (if applicable) for the project. If all milestone submissions have been merged for a project, please wait till October 15th for the selection of the team that will receive the best solution reward for each completed project.

Judging Criteria

Community Impact

  • How will developers or existing Flow users benefit from your solution?
  • Is your solution well documented and written in a way that makes it easy for others to understand and contribute?

User & Developer Friendly

  • Is your solution clear, accurate, and comprehensive to the problem you are solving?
  • How easy is your solution to use and/or integrate (if applicable)?

Quality & Excellence

  • Is your solution written in a way that is (or considers) stability, maintainability, and extensibility?
  • Does your code contain best practices of the language used? Does it adhere to the standards and contribution guidelines of the maintainers?

Comply with what the track needs

  • Each track has its own specific requirements and guidelines that must be complied with in order for the work to be considered successfully submitted.
  • Participants will have the opportunity to interact directly with Flow developers that will ensure you have a clear understanding of the problem, requirements, and validation of your solution every step of the way. Ultimately, the maintainers of the existing code will be responsible for assessing the specific requirements and the high-level criteria described above.

Got questions about Flow FLIP Fest?

We'll be hosting a special FLIP Fest Discord Office Hours session on Friday, 9/17 @ 8am PT | 11am ET to answer your questions and share more about FLIP Fest. Here’s how you can join:

Join the Discord Office Hours voice channel to listen in & ask your questions live

Livestream of Discord Office Hours will be live on 3 platforms:




We’ll also be hosting Daily Discord Drop Ins where you can ask your general registration questions and connect with the point of contact for each backlog issue.

Thursday, September 16th

10:00 AM - 12:00 PM EST - sideninja: Gregor Gololicic

3:00 PM - 4:00 PM EST - 10thfloor: Mackenzie Kieran

Friday, September 17th

2:00 PM - 3:00 PM EST- joshuahannan: Joshua Hannan

Saturday, September 18th

10:00 AM - 11:00 AM EST- MaxStalker: Maksim Daunarovich

11:00 AM - 12:00 PM EST - Srinjoyc: Srinjoy Chakraborty

Monday, September 20th

5:00 AM - 6:00 AM EST - bebner: Ben Ebner

3:00PM - 4:00 PM EST - gregsantos: Greg Santos

8:00 PM - 9:00 PM EST - psiemens: Pete Siemens

Tuesday, September 21st

12:00 PM - 1:00 PM EST - sideninja: Gregor Gololicic

11:00 PM - 12:00 AM EST- psiemens: Pete Siemens

Wednesday, September 22nd

12:00 PM - 1:00 PM EST - sideninja: Gregor Gololicic

1:00 PM - 2:00 PM EST - MaxStalker: Maksim Daunarovich - CANCELLED

11:00 PM - 12:00 PM EST - 10thfloor: Mackenzie Kieran

Thursday, September 23rd

12:00 PM - 1:00 PM EST - MaxStalker: Maksim Daunarovich

11:00 PM - 12:00 AM EST - psiemens: Pete Siemens

2:00 AM - 3:00 AM EST - bebner: Ben Ebner

Friday, September 24th

1:00 PM - 2:00 PM EST - joshuahannan: Joshua Hannan - CANCELLED

If you have questions specific to a backlog issue we ask that you join the Drop In led by the appropriate point of contact, but if you cannot make it you are welcome to join one of the other Drop Ins and we will try our best to answer your questions.

Please note that we currently only plan on doing Daily Discord Drop Ins for the initial registration stage, if you have questions throughout the hackathon we recommend connecting directly to the point of contact of the specific issues, asking your questions in FLIP Fest Discord or joining our regularly scheduled Office Hours on Fridays at @ 8am PT | 11am ET.

Ready to get started? Sign up for the Flow FLIP Fest today!