This integration needs to run at end-of-month and ETL 350,000 records...

End of which month? By my math, it would take 272 days to do 350k records at that rate. All seriousness, I would push back hard on your Oracle/NS Account Manager. That's ridiculous.

It's a Boomi issue, not a NetSuite issue. First step is to tidy up the lookups into Salesforce, next step is to purchase some concurrent cores (not sure what they call it) from Boomi.

Good luck! Would love to know how this goes for you, as we're looking at Boomi and others atm.

Latest testing shows 1000 records in 4 minutes.

Sounds like it's had an improvement though! Hopefully there are more improvements to get it where you need it to be! Was it the Boomi concurrency cores that have made the change from 50 in 56 to 1000 in 4? (if you don't mind me asking)

Yeah, it looks like the addition of 10 cores (or whatever the Boomi terminology is) has made that difference.