//www.martinrichards.me/tags/scalability/ Recent content in Scalability on Martin C. Richards Hugo en Sun, 18 Jan 2026 12:00:00 +0200 //www.martinrichards.me/post/ledger_p2_scaling_double_entry_ledger_massive_psp/ Sun, 18 Jan 2026 12:00:00 +0200 //www.martinrichards.me/post/ledger_p2_scaling_double_entry_ledger_massive_psp/ <h1 id="scaling-a-double-entry-ledger-for-a-massive-psp">Scaling a Double-Entry Ledger for a Massive PSP</h1> <p>In <a href="//www.martinrichards.me/post/ledger_p1_optimistic_locking_real_time_ledger/">Part 1</a>, we built a real-time double-entry ledger using optimistic locking. We benchmarked it and found it handles <em>160-440 req/sec</em> depending on contention, with zero errors and stable tail latencies. But benchmarks on localhost are one thing. <strong>Production at PSP scale is another.</strong></p> <p>This post answers the question: <em>Can this architecture handle a massive Payment Service Provider processing 10 million transactions per day?</em> Spoiler: <strong>Yes, but only if you get the account hierarchy right.</strong></p>