Why I'm Building a Production Go Payment Ledger (And You Should Too)
What a 600 taka dinner debt taught me about the system every fintech is built on, and why I'm spending twelve weeks building one in public
Jun 11, 20267 min read32
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Building go-ledger
Kicking off a 12-week build of an open-source, production-grade payment ledger in Go: double-entry accounting, Postgres, gRPC, OpenTelemetry, and a real deployment.
Modeling Double-Entry Accounting in Go: Types That Make Invariants Impossible to Violate
If a transaction that doesn't balance can't even be built without the compiler and a tiny Validate method noticing, a whole category of money bugs just stops existing
Jun 15, 20269 min read2
Postgres Schema for a Multi-Tenant Ledger: The Trade-offs No One Talks About
Your bank balance is not a number someone saved, it's a question the database answers by adding up your whole history, and that one design choice decides almost everything else
Jun 29, 20269 min read1
Atomic Transaction Posting in Go: Getting Balance Invariants Right Under Concurrency
An afternoon where one in six payments mysteriously failed, and the one-line database change that fixed it taught me more about Postgres than a year of reading docs
Jun 29, 20269 min read
Designing a REST API for a Payment Ledger: Resources, Verbs, and Why I Avoided GraphQL
The running-balance line in your banking app looks like a stored number, but building it taught me more about pagination and window functions than any tutorial ever did
Jun 29, 202610 min read6
Idempotency Keys and the Immutable Audit Log: Two Patterns That Make Fintech APIs Boring (In a Good Way)
You have tapped Pay twice when the app froze and then held your breath. This week I built the two things that mean you never get charged twice, and that anyone can prove it later.
Jul 2, 20269 min read