Principle · Understand
Financial Process Optimisation
How do you make a critical financial process faster without compromising accuracy?
A daily interest calculation was running too long, and customers were feeling it.
Measured outcome
~13 hrs → <1 minCalculation runtime
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Financial Process Optimisation
How do you make a critical financial process faster without compromising accuracy?
A daily interest calculation was running too long, and customers were feeling it.
1The challenge & my answer
It took about 13 hours. Payments could start before the interest was ready, so customers were paid short and credited late.
What looked like a performance issue was really a financial accuracy and customer experience problem.
I restructured how the calculation retrieved its data, aggregating once, reusing prepared datasets and simplifying the daily loop, without changing the financial rules. The runtime fell from about 13 hours to under a minute, and a 3am check now confirms the data is ready before payments run.
2The visual story
☞Press Run Both Versions to watch the old and new process side by side.
Illustrative timeline. Press run, then switch to After.
3My reasoning
- Traced it back. I followed customer payment discrepancies through the workflow. Execution logs showed the calculation taking around 13 hours.
- Found the real bottleneck. The interest rules were sound. The problem was repeated scans of a large transaction table, unnecessary loops and logic that recalculated values multiple times.
- Kept the financial logic intact. I chose to preserve the existing calculation rules and change only how data was retrieved, organised and processed.
- Validated in two stages. First in a test environment against manual calculations and historical dates, then with a non-writing version run against production data.
- Added visibility. There was no completion check, so failures surfaced as customer complaints. A 3:00 am check now confirms the data is there.
4Technical deep dive
Show the Technical Detail
Synthetic example of the pattern, not the production code.
5Outcome & reflection
- Measured
Runtime cut from about 13 hours to under one minute.
- Observed
The downstream process no longer made incomplete interest payments.
- Observed
Less manual investigation of missing accruals and payment discrepancies.
- Observed
Earlier warning: delays can be spotted before downstream processing starts.
ReflectionA calculation can be financially accurate but operationally inefficient. Next time, I would add an independent check on the calculated values, designed so it doesn't eat into the performance gains.