Paham Pajak
Lead Full-Stack AI Engineer
An advanced Indonesian tax consultation platform featuring an AI advisor powered by Google Gemini and RAG. Tightly integrated with 7 robust tax calculators and a real-time analytics dashboard, Paham Pajak simplifies complex financial regulations through an intuitive, data-driven architecture.
Core Technologies
Dynamic Tool Routing
& RAG Integration
Tax laws are dense and frequently updated. I architected a system utilizing Retrieval-Augmented Generation (RAG) over the DJP Coretaxpedia via Google Gemini's File Search Store.
Optimizing Token Costs
Handling high-volume AI queries requires aggressive cost management. I designed a dynamic tool routing strategy that inspects user messages and selectively injects context tools (`fileSearch`, `codeExecution`) only when required by the query intent.
For example, simple greetings skip tool injection entirely, saving significant prompt tokens. This intelligent routing is combined with a Redis-backed rate limiter and IDR-based user quotabuckets.
01 INTENT PARSING
Inspect incoming user query for math/tax keywords.
02 TOOL SELECTION
Inject `fileSearch` for regulations; `codeExecution` for math.
03 SSE STREAMING
Stream Gemini response via Server-Sent Events (SSE).
04 COST TRACKING (Usage Logs)
Calculate 5 token types → Update user IDR quota via Drizzle ORM.
Tax Planner Dashboard
Personalized Financial Strategy
The central user hub combining interactive quick estimating tools and financial summaries. It features a dedicated Tax Planner interface that hooks directly into the AI consultation engine to generate personalized, data-driven tax strategies.
- Interactive Tax Planner interface
- Real-time financial metric summaries
- Direct routing to AI Consultation
- Responsive grid layout via Tailwind v4
AI Tax Consultation
RAG + Gemini File Search
Conversational interface powered by Google's Gemini-3-flash. Answers are grounded in the official DJP Coretaxpedia regulations loaded locally via RAG. The UI actively parses markdown responses to inject dynamic 'Navigation Step' cards (e.g. Langkah 1, Langkah 2) for complex tax-filing workflows.
- RAG via Gemini File Search Store
- Dynamic Tool Routing logic
- SSE Streaming for real-time latency
- Interactive step-by-step navigation cards
Comprehensive Tax Calculators
Complex Financial Logic
Includes 7 fully interactive tax calculators (PPh 21 TER, PPh Badan, PPh UMKM, PPN, etc.). This feature handles dynamic TER rate tables and PTKP (Non-Taxable Income) values seamlessly across the Next.js React 19 Frontend.
- 7 distinct calculation modules
- Server-side state validation
- Real-time cost updates
- Clean shadcn/ui integration
Core Technologies
Next.js 16
Framework
React 19
Library
Gemini API
AI LLM
PostgreSQL
Database
Drizzle ORM
Schema/Types
Redis
Cache/Rate Limiting
Better Auth
Security
Tailwind v4
Styling
Recharts
Data Viz
Architecture & Implementation
Paham Pajak showcases a rigorous, production-ready implementation of modern Next.js alongside advanced RAG AI integration and optimized real-time data flow.