I'm on the growth team at Modern Treasury. Using our Ledgers and Payments products together could definitely help here. Ledgers is actually free to get started. The startup plan includes 5000 transactions a month and is free forever and the enterprise plan has volume-based pricing. We'd love to chat more about your use case and pricing. Feel free to drop a note - pranav@moderntreasury.com.
Don't want to hijack the thread here but we're building an open-source platform that includes ledgers and a scripting DSL for money movements at Formance, with payments connectors in beta and coming up for recon - always keen to chat
Mentioned this above but I'm a co-founder of Proper Finance https://www.properfinance.io where are building integrated ledgering and reconciliation software for fintech companies. We are happy to help where we can - the team were early engineers at Marqeta where we built the ledger, as well as reconciliation and financial controls. Shoot me a note - travis@properfinance.io
Not sure about payments integration though.
https://github.com/coilhq/tigerbeetle