Cardano Developer Use Cases: Holiday Season Challenge

Good, enjoyable challenges have a way of leaving people wishing for more. So, after the success of the Cardano Summit Layer Up hackathon, we really felt in the mood to put together another hacking challenge sooner rather than later.

The Cardano Foundation invites you all to a special festive season challenge.

20+ common blockchain use cases

This year the Foundation created a dedicated, open-source repository to provide developers building on Cardano with practical learning materials. All entries focus on concrete blockchain applications to use in everyday scenarios.

The repository includes:

• 21 of the most common blockchain use cases;
• on-chain and off-chain examples;
• implementations using multiple languages, tools, and frameworks;
• a consistent directory structure to help newcomers onboard faster.

The Foundation wants to make building on Cardano easier and more straightforward for newcomers. That means less abstract theory, way more practical reference implementations. At the same time, we aim to expand community participation and encourage diverse approaches across tools and frameworks.

So we created a challenge to accelerate the completion of these use cases. It’s designed to:

1. Strengthen developer experience and onboarding
   The more real working examples exist, the faster newcomers learn and the easier developers can move from interest to production.
2. Promote diverse implementations
   We welcome multiple languages, frameworks, and approaches. Different implementations of the same use case are not only valid but encouraged.
3. Increase open contributions from the ecosystem
   The challenge gives everyone a clear path to contribute immediately as well as an incentive to do so.
4. Increase the visibility of reference material
   By highlighting this repository, the challenge helps establish a long-term reference hub for developers.

Challenge details

This hacking holiday special will open today, 2 December 2025, and close on 16 January 2026 at 23:59 UTC.

Participants can select any of the use cases documented in the repository and submit:

• new on-chain implementations, or/and
• new off-chain implementations, or/and
• alternative implementations for use cases already completed using different tooling.

There is no limit to the number of solutions submitted by each participant.

We’ll also accept any languages and frameworks commonly used in the Cardano ecosystem.

On-chain examples include: Aiken, OpShin, Scalus, Pebble, Plutarch, Plinth, and others.

Off-chain examples include: Mesh, Blaze, Cardano Client Lib (CCL), Scalus, Evolution, PyCardano, and others.

Submission process

All submissions must happen via pull request to the public repository.

Make sure to follow the required steps:

1. Fork or clone the repository.
2. Create/place a new implementation in an appropriate directory folder, e.g.:
   /aiken, /mesh, /plutarch, etc.
3. Include a README with:
   • description of the use case;
   • framework or tool used;
   • how to build, run, and test the implementation;
   • notes on architecture, design decisions, or limitations.
4. Push changes .
5. Open a pull request to the main branch of the main repository.

Each pull request will be reviewed and scored individually.

Prizes and regulations

The Foundation’s engineers will evaluate each submission, considering technical correctness, design decisions, and alignment with Cardano best practices. This means we’ll focus on:

• Technical execution: whether the code functions correctly, is robust, and well structured.
• Cardano application: appropriate and meaningful use of Cardano’s capabilities.
• Documentation: clarity of the README and usefulness to future developers.
• Reproducibility: ease with which reviewers can run the project.

After verifying the eligibility of the implementation pull request, we’ll start with a simple scoring system:

• 1 point per on-chain implementation
• 1 point per off-chain implementation
• 1 bonus point per implementation in the case of submissions for use cases without any on-chain/off-chain implementation at the start of the contest period.

The following requirements and rules will also apply:

• All submissions must be original work created during the challenge period.
• Use of open-source libraries is permitted, provided licensing is respected.
• Documentation must be in English.
• Code must compile or run successfully based on the instructions provided.
• Participants may submit multiple independent pull requests.
• Only participation by individuals is allowed (no teams).
• Submissions must not include illegal or malicious content.
• Participants must behave lawfully and ethically when participating in the challenge.
• Cardano Foundation employees, consultants, interns, and contractors can participate in the challenge for learning and contribution purposes; however, they are not eligible for prize awards or rankings.

We’ll announce the winners on 30 January 2026 at 9:00 UTC, during our Cardano Developers Office Hours. The two winning contributors will receive:

• first place: US$1,000
• second place: Cardano Tiamond NFT

Bear in mind that winners may be required to fulfil certain conditions, including identity and KYC verification, in order to receive the prize.

For now, the Foundation wishes everyone a merry season and a great hacking time. Let’s get coding!