Notes
Short write-ups about systems I have designed and the decisions behind them.
October 22, 2026 · 6 min read
A distributed join across SAP BTP and S/4HANA in a single ERP round trip
How the Penguin procurement portal lists purchase orders by a collaboration status that lives only in PostgreSQL on SAP BTP, while every field on screen lives only in SAP S/4HANA: a distributed semi-join, a key set shipped in one OData call, and a join, aggregation and paging step in CAP.
October 20, 2026 · 3 min read
From payment webhook to fiscal document with a transactional outbox
How Instant turns every confirmed dLocal payment or refund into exactly one DGI e-invoice: a transactional outbox, an SQS relay, and an invoicing service that records first and checks InvoiCy before every send.
October 20, 2026 · 2 min read
A personalized job feed with two-tower embeddings on Bedrock and pgvector
How Instant ranks jobs for each worker and applicants for each company: embeddings and scores are computed by SQS-driven workers on AWS Bedrock, so reading the feed is a single PostgreSQL query.