Your question is Idempotent Recurring Posting Pipeline. Take a moment with it on the right.
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You are working on a recurring posting pipeline for a finance workflow. The process reads scheduled payment records, applies them to downstream accounting tables, and may retry after partial failures. A duplicate run can create double postings, so the pipeline needs a clear way to detect replays and keep the ledger correct.
How would you make sure a recurring posting process is idempotent so payments are not applied twice?