Part 1 — Context Engineering: Domain-Driven Design for AI

Prerequisite: Familiarity with the concepts introduced in Executive Summary. Review it first if the terminology in this part is unfamiliar. Answer-first: Context Engineering structures, scopes, and injects software domain knowledge into Large Language Model prompts using Domain-Driven Design principles. By organizing codebases into explicit Bounded Contexts, Abstract Syntax Tree subgraphs, and JSON-Schema contracts, engineering teams eliminate hallucinations, enforce layer boundaries, and enable autonomous coding agents to implement production-grade enterprise features. ...

March 16, 2026 · 9 min · Lê Tuấn Anh

PayPay AI Platform: Machine Learning & Fraud Engine

Prerequisite: Familiarity with the concepts introduced in Part 5 — Campaign Architecture. Review it first if the terminology in this part is unfamiliar. Answer-first: Integrating AI capabilities into payment platforms involves embedding real-time LLM RAG hubs for customer support and ML fraud detection models into transaction evaluation pipelines, enforcing sub-20ms model inference SLAs. Answer-first: PayPay integrates AI into its transaction pipelines by streaming payment events asynchronously to machine learning scoring models. Running inference out-of-band prevents risk assessment evaluations from adding latency to the synchronous checkout flow, enabling real-time fraud detection and dynamic credit scoring. ...

May 5, 2026 · 10 min · Lê Tuấn Anh

Prompt Engineering vs Fine Tuning: 2026 AI Decision Guide

Prompt Engineering vs Fine Tuning vs RAG: Complete 2026 Decision Guide Prompt Engineering vs Fine Tuning: Executive Decision Framework Answer-first: In the prompt engineering vs fine tuning evaluation, prompt engineering offers rapid prototyping with zero setup cost, whereas fine tuning Small Language Models (SLMs) via QLoRA bakes domain knowledge into weights, reducing TTFT latency under 250ms and cutting API token spend by 90%. Small Language Models (SLMs, 1B–8B parameters) combined with fine-tuning and local inference (vLLM) rival proprietary frontier LLMs on specialized domain tasks at a fraction of the cost. The playbook below rests on three architectural choices: ...

June 1, 2026 · 9 min · Lê Tuấn Anh

Autonomous Hybrid-AI Pipeline: Cron to State-Machine

Autonomous Hybrid-AI Pipeline: Cron to State-Machine Production AI content pipelines need deterministic orchestrators, multi-tier memory systems, and cost-aware model routing to handle automated ingestion reliably. Replacing monolithic background jobs with event-driven agents gives resilient execution, zero-idle resource usage, and stricter output verification. This post covers four pieces of that architecture: Topology & Orchestration: Master-worker agent swarms managed by explicit state machines. Memory System Architecture: Working memory (context window), short-term memory (Redis session), and long-term memory (Vector/Graph RAG). Tool Calling & MCP: Protocol-driven tool execution via Model Context Protocol. AgentOps & Governance: Tracing, fallback cascades, evaluation gates, and hardware Wake-on-LAN power optimization. 1. Agent System Topology & State Machine A resilient pipeline replaces stateless cron scripts with an explicit Finite State Machine (FSM). By encapsulating pipeline operations within state transitions, every step—from hardware boot to scraping, filtering, and drafting—is recorded with atomic rollback safety. ...

May 18, 2026 · 8 min · Lê Tuấn Anh

The Disruption of Naive RAG & Enterprise GraphRAG Era

Executive Summary: The Disruption of Naive RAG and the GraphRAG Era Answer-first: Naive RAG collapses in enterprise environments due to relational blindness, unstructured document chunk destruction, and lack of fine-grained access control. Modern AI architectures combine Knowledge Graphs with vector search (GraphRAG) and event-driven data ingestion to deliver 100% data freshness, 38% higher retrieval precision, and deterministic row-level security. Key Takeaways: 38% Higher Precision: GraphRAG entity-relation traversal resolves multi-hop enterprise queries where vector similarity alone fails. Hybrid Indexing Pattern: Combining HNSW vector indices with property graph databases (Neo4j/Memgraph) yields sub-50ms query resolution. Continuous Evals: Embedding LLM-as-a-Judge CI/CD gates enforces Faithfulness >= 0.85 and Context Precision >= 0.90 prior to production deployment. If you have ever built an internal chatbot for your enterprise by chunking raw markdown or PDF documents, creating dense embeddings with OpenAI text-embedding-3-small, and persisting them into Pinecone, Qdrant, or Milvus, you have inevitably encountered the systemic limitations of Naive RAG (Retrieval-Augmented Generation): ...

May 17, 2026 · 9 min · Lê Tuấn Anh

LeaseInVietnam: AI-Powered Expat Rental & B2B Lead Engine

LeaseInVietnam: AI-Powered Expat Rental & B2B Lead Engine Most AI content projects are built around one question: how do I publish more? LeaseInVietnam is built around a different question: how do I make every published piece convert? The system is an autonomous relocation hub targeting expats and digital nomads renting in Southern Vietnam — Ho Chi Minh City, Nha Trang, Phú Quốc. It produces content in American English, publishes daily via GitOps, and routes every reader interaction toward a B2B lead funnel that pays commission on moving services, cleaning bookings, furniture rentals, and legal consultations. ...

April 24, 2026 · 14 min · Lê Tuấn Anh