Topic Hub

Architecture

High-level system design, edge compute patterns, database scaling, and technical decisions behind enterprise applications.

Current note

The broker pattern is older than the agentic-commerce headline

The newest published argument and its visual artifact lead the page.

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Editorial posture

The library is organized around decisions that keep recurring in payment architecture, AI systems, and Doric product work. New notes lead by publish date, while topic lanes connect related arguments without turning the index into an archive wall.

Decision frame

Recommendation, rejected paths, and the operating proof behind the call.

Visual proof

Diagrams and original artifacts stay near the argument they explain.

Source posture

Public claims stay tied to released work or cited material.

Architecture

The broker pattern is older than the agentic-commerce headline

Stripe Shared Payment Tokens are the agentic-commerce headline, but anyone who ran a card tokenization rollout in 2014 recognizes the shape in five seconds. A scoped surrogate credential with a thin stable interface in front and brokered complexity behind is not new. Visa Token Service shipped it twelve years ago, and the architects who see the pattern early build the right systems instead of rebuilding every eighteen months.

Lead essay

The current Doric argument leads the index ahead of the chronological archive.

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01 / Payments

Commerce architecture

Merchant-of-record decisions, checkout ownership, billing operations, settlement, reconciliation, and risk boundaries.

02 / AI tooling

Practical AI systems

Agentic commerce, multi-agent orchestration, model fine-tuning, runtime governance, and production deployment.

03 / Build notes

From idea to system

The design, architecture, and operating decisions behind Doric Stack products as they move from prototype to public release.

Latest Notes

All

Jul 2, 2025 By Navin Agrawal Architecture 2 min read

Tokenized money is a 2025 architecture problem, not a 2030 one

The BIS just blueprinted a tokenized unified ledger and JPMorgan put a deposit token on a public chain - in the same week. The hard part for banks was never the blockchain. It is retrofitting core banking to carry programmable money without a big-bang migration.

Jun 25, 2025 By Navin Agrawal Architecture 3 min read

Cross-platform integration: the patterns that actually hold

Fiserv, Bottomline, and a core banking system each work fine alone. Wiring them into one payment chain is where projects go to die - and the difference between the ones that survive and the ones that become expensive lessons is a handful of boring resilience patterns.

Jun 10, 2025 By Navin Agrawal Architecture 3 min read

Why your payment modernization is backwards

Most banks modernize core-first and treat compliance as the finish line. With Fedwire going ISO 20022-native in July 2025, that order is exactly backwards - compliance is the foundation, not the finish.