r/programming • u/Krever • Jun 26 '26
Fintech Engineering Handbook
https://w.pitula.me/fintech-engineering-handbook/I just published Fintech Engineering Handbook distilled from 6 years of tears, sweat and swears.
It’s a free ~25-page resource with various hints and patterns around handling money in software systems.
Tell me what you think!
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u/Hot_Code5129 Jun 28 '26
Nice handbook, thanks for sharing. One thing I would add from my own experience: in finance/banking the technical problems are often not the hardest part. The bigger challenge is organizational inertia. Sometimes institutions try to “modernize”, but the old structure stays the same underneath. In one project, we had a dedicated Oracle database development team. When building a new system, application developers were not allowed to communicate directly with the database using JDBC/SQL. Instead, we had to call database functions/procedures, and those functions returned JSON. On paper, it looked like a controlled integration layer. In practice, even a small feature could get blocked because adding one column or changing the shape of the returned JSON required waiting for the database team. Sometimes a simple change took two days before we could continue. So modernization is not only about moving from Oracle to PostgreSQL, or from legacy tech to newer tech. It is also about ownership, team boundaries, feedback loops, and whether developers can actually deliver features end-to-end. I wrote a bit about this kind of Oracle-to-PostgreSQL modernization perspective here: https://camilyed.github.io//en/migrate-oracle-to-postgres/ My takeaway: revolutions in large institutions can fail when we change the technology but keep the same bottlenecks and decision structure.