Building a Financial Planning Platform

March 14, 2026 · 3 min · nickelpie.com

What Is NickelPie?

NickelPie is a financial planning platform built for everyone, not just people with a finance background. It brings together budget tracking, investment insights, and goal setting in a single dashboard. The idea is straightforward: give people a clear picture of where their money goes, where it could grow, and how to reach the financial goals that matter to them.

Architecture Overview

Financial data requires strong security and reliable performance. NickelPie runs on a serverless AWS stack with Cognito handling authentication so user credentials are managed by AWS rather than custom code. All API requests pass through API Gateway to Lambda functions that read and write financial data in DynamoDB.

User Browser
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CloudFront (Static Assets from S3)
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Cognito (Authentication)
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API Gateway (REST API)
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Lambda Functions (Budgets / Goals / Investments / Analytics)
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DynamoDB (User Data, Budgets, Goals, Transactions)

Every API endpoint is protected by Cognito authorizers, ensuring that users can only access their own financial data. The static frontend is served from S3 through CloudFront for fast global delivery.

Key Features

Budget Tracking lets users categorize income and expenses, set monthly limits per category, and see at a glance how they are tracking against their plan. Transactions are stored in DynamoDB with date-based sort keys, making it efficient to query spending by week, month, or custom date range.

Investment Insights provide a simplified view of portfolio performance. Users can log their holdings and see historical trends, allocation breakdowns, and basic projections. The data is processed by Lambda functions that calculate returns and generate visual summaries on the dashboard.

Goal Setting turns financial ambitions into actionable plans. Users define a target amount and timeline, and NickelPie calculates the monthly savings needed. Progress is tracked automatically based on budget data, and the dashboard shows how each goal is trending relative to its deadline.

Performance

Dashboard loads complete in under one second thanks to CloudFront edge caching and efficient DynamoDB queries. Cognito authentication adds minimal overhead since tokens are validated at the API Gateway layer without invoking Lambda. Budget calculations and goal projections run in Lambda with average execution times under 100ms. The serverless model means costs scale directly with usage, keeping the platform affordable to operate.