Fintech Engineering Handbook (w.pitula.me)

Article summary

The Fintech Engineering Handbook provides guidance on building software that handles money, covering principles such as no invented data, no lost data, and no trust. It discusses topics like representing money, precision handling, rounding strategies, and currency handling. The handbook aims to help developers build trustworthy money systems. It also covers more advanced topics like double-entry bookkeeping, audits, and event sourcing.

Main themes

• Fintech engineering principles
• Money representation
• Precision handling
• Currency handling
• Audit trails
• Event sourcing

What commenters say

• Idempotency is a crucial concept in fintech engineering that can save companies from potential issues.
• Audit trails are essential for debugging and compliance, and can be a last resort for data source verification.
• Using minor-units precision for representing monetary amounts can be problematic, especially when working with partners that have different implied number of digits for a given currency.
• Storing monetary amounts as strings can be a better approach than using floating-point numbers or integers to avoid precision issues.
• Explicitly defining decimal places in data representation can help avoid semantic complexities and assumptions about what the data supports.
• Optimizing for correctness over performance is often preferred when dealing with monetary amounts to avoid potential discrepancies.
• Throwing away precision in finance computations should be done rarely and with well-defined points to avoid large discrepancies.
• Using a specific data type, such as decimal, can help ensure accurate computations and avoid precision issues.