Dev builds serverless compound interest calculator using pure browser-side JavaScript

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An indie developer has built a compound interest calculator that runs entirely in the browser using plain JavaScript, with no backend, server, or external dependencies. The tool accepts a principal amount, interest rate, compounding frequency, and timeframe to calculate future savings value using a standard compound interest formula. A key technical challenge was handling a division-by-zero edge case when the interest rate is set to zero, which initially caused the app to display NaN before a fallback was added. The developer also wrote a custom SVG chart generator to visualize growth over time, avoiding popular libraries like Chart.js to keep the project fully self-contained. The single-file HTML app can be hosted on any static platform at no cost, and user financial data never leaves the browser.

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