The PayEng Playbook

A ledger is not just an accounting compliance tool — it's a system that builds financial intelligence within a company. Early-stage startups don't need ledgers; the only metric that matters is runway. Post product-market fit, however, tracking where money goes and why becomes critical as ROI conversations replace pure growth metrics. The post outlines five concrete indicators that signal it's time to move from spreadsheets to a ledger system: transaction volume approaching 1,000/month, 40+ hours to close quarterly books, 1%+ discrepancy rate, finance team spending 20% of time on reconciliation, and projected 50%+ transaction growth. The core tension in any ledger is between accounting's need for correctness and engineering's need for scale and throughput. When built correctly, a ledger shifts from answering 'where did money go?' to 'where should money go next?'

You Don't Know What a Ledger is For

When to ditch the spreadsheet and build a ledger