I think it is more intuitive to throw errors for unexpected behaviours instead of returning undefined and then we don't what happened. Also, would remove the need to have decoding and then undefined checks in saveEvents
Probably decoding errors will need to be caught and handled appropriately in saveEvents and logged as warn as we most likely don't want to try decoding that again, but at least we will know what happened.

Hm, I might've made a bad approach for the whole workflow then. But what this is essentially doing is checking if the output address is the relayer address (resourceFound) and if it is, it parses and returns the data so it can be stored in the database. If it isn't, it returns undefined. So it'll return undefined for every transaction that isn't actually a Sygma deposit.

Add some description of where and why it happened.

Coinmarketcap service functions already log the whole URL that was unsuccessfully fetched and additionally throw the message Error getting value from CoinMarketCap which is shown to be caught and logged here so not sure should I provide any more context?

I feel like we have this logic somewhere else as well.
See if it can be reused instead of copied.

Yes, something like getUpdatedTransfer function was in the squid-indexer repo. Just, that would require a partial refactor of evm and substrate parts also, so not sure should I do it in this PR ?

If it is a big refactor I would avoid it/do it separetly for now.

I think it's better to do it in a separate PR. Along with refactoring saveProposalExecution functions.

A lot of this save functions have basically the same logic as other networks.
Would be prudent to check if it can be unified.

I think it's better to do it in a separate PR. Along with refactoring saveDeposit functions.