The problem PapaBase solves

PapaBase is a crowdfunding platform dedicated to support builders making and maintaining public goods and open source projects.
Builders and devs contributing to open source projects struggle with receiving donations to support their work. The existing few platforms do not allow donations by fiat but only by crypto, furthermore making it less accessible for non-crypto users.
PapaBase uses USDC as the default receiving token for any campaign. However, people can donate in different tokens and the amount is automatically converted into USDC or they can easily make an on-ramp using Coinbase Pay.

In addition, current platforms do not give tools for donors to stay up to date on the project or be able to talk to the builder(s). PapaBase donors access a token-gated chat (XMTP) with the project builders being able to stay up to date with the project with both automated and manual updates.

Challenges we ran into

We didn't find any particular bug or hurdle while developing PapaBase. Everything was quite smooth other than the "standard" hackathons problems when using new technologies.
The only thing is that too often projects are deployed on different chains and different testnets. This make very very difficult to test apps on testnet and we needed to go on mainnet spending real money. So please projects talk to each other to support all the main testnets.