Sophisticated full-stack web application combining advanced tax calculation algorithms, real-time currency conversion, and conversion-optimized content marketing.
InterLaw is a sophisticated full-stack web application providing international tax optimization services and legal residency planning. The platform combines advanced tax calculation algorithms with content marketing, lead generation, and client consultation booking to serve high-net-worth individuals and digital nomads seeking legitimate tax optimization strategies.
Next.js 15 (App Router)
├── Server-Side Rendering (SSR)
├── Static Site Generation (SSG)
├── TypeScript for type safety
├── Tailwind CSS for styling
└── Framer Motion for animationssrc/
├── app/ # Next.js App Router
│ ├── blog/ # Content marketing
│ ├── calculator/ # Tax tools
│ └── layout.tsx # Root layout
├── components/
│ ├── calculator/ # Tax calculation UI
│ ├── sections/ # Landing sections
│ └── ui/ # Reusable components
├── data/
│ ├── strategies.ts # Tax strategies
│ └── taxRates2025.ts # Tax brackets
├── hooks/
│ ├── useAnalytics.ts # Analytics
│ └── useExchangeRates.ts # Currency
└── utils/
└── taxCalculations.ts # Tax logicThe core innovation is a sophisticated tax calculation algorithm handling progressive tax brackets for 15+ countries with varying structures.
// Complex tax calculation algorithm handling progressive brackets
const calculateTax = (brackets: TaxBracket[], amount: number): number => {
let remainingIncome = amount
let totalTax = 0
for (const bracket of brackets) {
const { min, max, rate } = bracket
const taxableAmount = max
? Math.min(Math.max(0, remainingIncome), max - min)
: Math.max(0, remainingIncome)
if (taxableAmount <= 0) break
totalTax += taxableAmount * rate
remainingIncome -= taxableAmount
if (remainingIncome <= 0) break
}
return totalTax
}
// TypeScript interfaces for type safety
interface TaxBracket {
min: number;
max?: number;
rate: number;
}
interface HomeCountry {
name: string;
currency: string;
taxYear: string;
brackets: TaxBracket[];
}// Advanced analytics tracking implementation
const trackCalculatorResults = (data: {
income: number;
country: string;
strategy: string;
annualSavings: number;
tenYearSavings: number;
monthsToBreakeven: number;
}) => {
// GTM event tracking with custom parameters
gtag('event', 'calculator_results_viewed', {
event_category: 'Calculator',
event_label: data.strategy,
value: data.annualSavings,
custom_parameters: {
income_bracket: categorizeIncome(data.income),
optimization_ratio: data.annualSavings / data.income,
roi_months: data.monthsToBreakeven,
target_country: data.country
}
});
// Conversion funnel analysis
trackConversionFunnel('calculator_completed', {
step: 'results_displayed',
potential_savings: data.annualSavings,
user_segment: getUserSegment(data.income)
});
}// Real-time exchange rate integration with caching
const useExchangeRates = () => {
const [rates, setRates] = useState<ExchangeRates>({});
const [loading, setLoading] = useState(false);
const [error, setError] = useState<string | null>(null);
const fetchRates = useCallback(async () => {
try {
setLoading(true);
// Check cache first
const cachedRates = getCachedRates();
if (cachedRates && !isStale(cachedRates.timestamp)) {
setRates(cachedRates.data);
return;
}
// Fetch fresh rates with error handling
const response = await fetch('/api/exchange-rates');
if (!response.ok) throw new Error('Failed to fetch rates');
const freshRates = await response.json();
setCachedRates(freshRates);
setRates(freshRates);
} catch (err) {
setError(err.message);
// Fallback to cached rates if available
const fallbackRates = getFallbackRates();
if (fallbackRates) setRates(fallbackRates);
} finally {
setLoading(false);
}
}, []);
return { rates, loading, error, refresh: fetchRates };
};Comprehensive data structures supporting multiple tax optimization strategies with detailed cost analysis and ROI calculations.
0% tax on foreign income, $4,400 setup cost
0% personal income tax, $19,000 setup cost
Territorial tax system, $15,000 setup cost
Problem: Implementing accurate progressive tax calculations for multiple countries with different bracket structures, edge cases, and varying tax years.
Solution:
Problem: Providing accurate, up-to-date exchange rates without compromising performance or user experience during high-frequency calculations.
Solution:
Problem: Generating SEO-friendly pages while maintaining dynamic functionality, calculator interactivity, and fast loading times.
Solution:
Custom hooks, context management, component composition, performance optimization
App Router, SSG, SSR, metadata API, image optimization, performance tuning
Complex type definitions, interface design, type safety across entire codebase
Complex tax calculations, progressive bracket handling, optimization algorithms
InterLaw demonstrates comprehensive full-stack development capabilities across multiple technical domains, showcasing the ability to build complex, conversion-optimized applications that solve real-world problems for international clients while maintaining exceptional performance and user experience standards.