KeeperKeeper
autonomous chainlink upkeeps manager
About
The problem it solves A smart contract that eliminates the need to monitor $LINK balances of Chainlink upkeeps on their dashboard. Necessary $LINK balances are topped up where needed---fully automatic.
How it's made
Challenges we ran into first time writing vyper :) - did not find a proper way yet to programmatically convert solidity contracts into a vyper interface - no actively maintained linter - manual states `__init__` cannot call internal contracts but it can - submitted https://github.com/vyperlang/vyper/issues/3166