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Writing
Notes on payment systems, device software, transaction uncertainty, platform design, and the emerging role of AI in commerce. I write from the questions that appear in real operating conditions.
Every payment platform ends up with a connector abstraction. The design choices that make one durable, and the ones that guarantee it will be rewritten in 18 months.
For commerce applications, an LLM answer without a citation is not an answer — it's a liability. The engineering pattern that actually works.
Verification of payee became mandatory across SEPA in October 2025. The first months in the field show a predictable pattern of edge cases.
PCI-DSS v4.0 is now mandatory. Beyond the well-publicised customized approach, several less-discussed changes shift how integrations should be built.
The engineer who is present but disengaged is a specific management problem. What's actually going on, and what a manager can do about it.
The Markets in Crypto-Assets regulation has been in full effect through 2025. Two years in, the operational patterns are becoming visible.
PCI's MPoC standard formalises PIN entry on off-the-shelf phones. The assumptions worth challenging in an integration review.
Reconciliation gets treated as a nightly batch afterthought. Elevating it to a first-class service changes what the rest of the platform can guarantee.
Terminal firmware breaks in patterns. Three rules would eliminate about half of the incidents I've been paged for.
The Federal Reserve's instant payment service crossed its third live year in July 2026. Adoption looks different from what the launch materials promised.