The Leanpub 60 Day 100% Happiness Guarantee
Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.
See full terms...
Money-Safe Go
Building Financial Software That Never Loses a Penny
This book is 100% completeLast updated on 2026-10-25
Floats that lose cents, payments charged twice, ledgers that don’t balance. This book shows Go developers how to write financial code that gets money right, with tested code for every pattern.
Minimum price
$24.99
$34.99
You pay
Author earns
PDF
EPUB
About
About the Book
If you write Go and your code touches money, this book is for you.
Money code fails differently from other code. A rounding slip, a retried request or a job that runs twice can mean a customer charged twice, a loan with the wrong interest, or a balance that’s been quietly wrong for years. The fixes aren’t secret, but they’re scattered across accounting textbooks, payment network rulebooks and the post-mortems of companies that got it wrong.
Money-Safe Go puts them in one place. You’ll learn to represent amounts exactly, handle business dates and cutoffs, build a double-entry ledger, charge exactly once with idempotency keys, survive concurrency and batch jobs, reconcile against the bank, and keep an audit trail. Later chapters cover real money flows: currencies, loan schedules, refunds and chargebacks, prepaid balances, webhooks, data migrations, bank returns, month-end close, and fraud limits. A capstone chapter builds a small payments service that brings it all together.
Every chapter opens with a real incident from public sources, and every listing comes from companion code that’s tested in Go and PostgreSQL. The code is free on GitHub.
Feedback
Author
About the Author
Daniel Marrera
Daniel Marrera, Jr has spent more than 40 years building banking, lending and collections systems, and about a decade writing Go. He wrote Money-Safe Go to collect, in one place, the lessons that usually take a career and a few painful incidents to learn.
Earn $8 on a $10 Purchase, and $16 on a $20 Purchase
We pay 80% royalties on purchases of $7.99 or more, and 80% royalties minus a 50 cent flat fee on purchases between $0.99 and $7.98. You earn $8 on a $10 sale, and $16 on a $20 sale. So, if we sell 5000 non-refunded copies of your book for $20, you'll earn $80,000.
(Yes, some authors have already earned much more than that on Leanpub.)
Learn more about writing on Leanpub
Free Updates. DRM Free.
If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).
Most Leanpub books are available in PDF (for computers) and EPUB (for phones, tablets and Kindle). The formats that a book includes are shown at the top right corner of this page.
Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.
Learn more about Leanpub's ebook formats and where to read them
Write and Publish on Leanpub
You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses!
Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks.
Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. (Or, if you are producing your ebook your own way, you can even upload your own PDF and/or EPUB files and then publish with one click!) It really is that easy.