Modeling TFSA, FHSA and RRSP Rules in Software
How I model TFSA, FHSA and RRSP contribution room in MapleWealth: ledgers instead of balances, carry-forward, re-contribution timing and the edge cases.
8 min read
Case StudyPrivate-First Personal Finance Dashboard for Canadians
Built with Next.js 16, TypeScript, Prisma, Better Auth, and PostgreSQL — a SaaS-ready wealth-management platform purpose-built around Canadian tax-advantaged accounts.
2025
Year
Full-Stack
Services
Next.js 16
Tech Stack
Fintech / SaaS
Category
Executive Summary
MapleWealth is a private-first, SaaS-ready personal finance dashboard and wealth-management platform built specifically for Canadian users. It automates tracking across tax-advantaged accounts (TFSA, FHSA, RRSP), projects net worth over time, applies rule-based savings and emergency-fund allocation, and supports CSV transaction imports with dividend tracking — all backed by structured financial analytics.
99
Lighthouse Performance
100
Lighthouse SEO
2.2s
Largest Contentful Paint
1.0s
First Contentful Paint
0
Cumulative Layout Shift
10ms
Total Blocking Time
The Challenge
Canada's registered account system (TFSA, FHSA, RRSP) has its own contribution rules and tax treatment, but most personal finance tools are built for a US audience and don't model these accounts correctly.
Key Problems Identified:
- •Account Modeling: Generic finance apps don't distinguish TFSA, FHSA, and RRSP contribution room, growth, and withdrawal rules
- •Fragmented Data: Users track net worth and transactions across multiple institutions with no unified view
- •Manual Allocation: Deciding how to split savings between an emergency fund and registered accounts is typically a manual, error-prone exercise
- •Privacy Sensitivity: Financial data is inherently sensitive, so the platform needed to be private-first by design, not as an afterthought
Mission Statement:
Give Canadians a single, privacy-respecting dashboard that actually understands TFSA, FHSA, and RRSP mechanics instead of treating them as generic savings accounts.
The platform needed structured account modeling, dependable auth, and a data layer that could support real financial analytics without compromising on privacy.
Solution
MapleWealth was built as a Next.js 16 application with Prisma over PostgreSQL for structured financial data, and Better Auth for secure, modern authentication.
Canadian-Native
Purpose-built modeling for TFSA, FHSA, and RRSP accounts instead of generic savings buckets
Private-First
Built around Better Auth with a data model designed for a single-tenant, privacy-conscious experience
Structured Analytics
Net worth projections and dividend tracking backed by a relational data model
Our Approach Focused on Three Core Pillars:
1. Canadian Account Modeling
- • Automated tracking for TFSA, FHSA, and RRSP accounts
- • Net worth projections over time
- • Dividend tracking with structured analytics
2. Practical Money Tools
- • Rule-based savings and emergency-fund allocation
- • CSV transaction imports
- • Structured financial reporting
Target Audience:
Primary: Canadian individuals managing TFSA, FHSA, and RRSP accounts
Secondary: Users who want a private, self-hosted-feeling alternative to consumer finance apps
Tertiary: SaaS-minded users looking for a wealth dashboard built around Canadian tax rules
Technical Architecture
Frontend Stack
- ✓Next.js 16 (App Router)
- ✓React
- ✓TypeScript (Full type safety)
- ✓Tailwind CSS
Backend & Data
- ✓Prisma ORM (Type-safe database access)
- ✓PostgreSQL (Structured financial data)
- ✓Better Auth (Modern authentication)
Deployment
- ✓Production hosting on Vercel
- ✓GitHub-hosted, open-source repository
Key Features & Innovation
Tax-Advantaged Account Tracking
Automated tracking purpose-built for TFSA, FHSA, and RRSP accounts.
• TFSA tracking
• FHSA tracking
• RRSP tracking
Net Worth Projections
Forward-looking projections of net worth based on tracked accounts and contributions.
• Structured projection model
Rule-Based Savings Allocation
Automated rules for splitting savings between an emergency fund and other goals.
• Emergency fund allocation
• Rule-based savings logic
CSV Transaction Imports
Bring in transaction history from external institutions via CSV import.
• CSV import pipeline
Dividend Tracking
Structured tracking of dividend income as part of overall financial analytics.
• Dividend tracking
• Structured financial analytics
Performance & Results
99
Lighthouse Performance
100
Lighthouse SEO
94
Lighthouse Accessibility
2.2s
Largest Contentful Paint
1.5s
Speed Index
0
Cumulative Layout Shift
These are live Lighthouse results captured directly against the production dashboard — a 99 Performance score and perfect 100 SEO score, with a 2.2s Largest Contentful Paint on a data-dense, chart-driven interface.
For a finance dashboard, keeping interaction latency low (10ms Total Blocking Time) matters as much as initial load — users are frequently switching between accounts and views, and the app needed to stay responsive throughout.
Business Impact & Results
Technical Performance
• 99 Lighthouse performance score in production
• Perfect 100 Lighthouse SEO score
• 2.2s Largest Contentful Paint on a data-heavy dashboard
• Zero cumulative layout shift
Financial Modeling
• Native support for TFSA, FHSA, and RRSP accounts
• Net worth projection tooling
• Rule-based emergency fund allocation
• CSV import and dividend tracking
MapleWealth shows that a Canadian-specific fintech tool doesn't need to sacrifice performance for domain accuracy — the platform models TFSA/FHSA/RRSP mechanics precisely while still shipping a fast, SEO-clean production build.
See wealth management built around how Canadian accounts actually work
Blog and articlesNotes from client work and side projects: architecture decisions, tooling and what shipped.
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