Sheet 07 · Engineering blog
Notes from building.
Learnings, tutorials, and the occasional teardown, from the engineering behind our client work. Written by the people doing it.
Sep 20, 2026The tenant fallback that served one company's books to anotherA multi-tenant finance platform refused to degrade in four places and fell back in one. The unit test covering that path was named as though it proved the opposite — and for months it held the bug in place.multi-tenancysecurityintegrationstestingSep 20, 2026Postgres holds the state, the queue holds the deliveryMost background-job bugs come from treating the queue as the system of record. Put the state in your database and let the queue do nothing but wake a worker, and at-least-once delivery stops being a problem you have to solve.architecturepostgresqueuesmulti-tenancyreliabilitySep 20, 2026One interface, three ERPs that agree on nothingOdoo, Zoho Books and ERPNext disagree about what a posted invoice is, where an idempotency key can live, and whether a document can be un-posted. Here is the adapter boundary that survived adding the third one.integrationsodoozohoerpnextarchitectureJul 2, 2026Two lines to see what your LLM is actually doingBefore we optimize anything in an AI build, we make it observable. Here is the one-minute version with peekr.observabilityllmpeekrJun 24, 2026Giving an AI agent memory that survives the sessionStateless agents forget everything the moment a chat ends. Here is how we give them real, queryable memory with extremis over MCP.agentsmemorymcpextremis