Existing Structure:
requirements.txt/pyproject.toml
✅ What You Did Well
1️⃣ Clear Separation of Concerns
You separated:
That’s correct layering for a GenAI backend.
You’re thinking in modules — good.
2️⃣ LLM as Its Own Module
This is very good.
You are treating LLM as a system component, not sprinkling calls everywhere.
That aligns with proper GenAI system design:
LLM = stateless inference component
RAG = architecture
Embeddings = infra layer
Good separation.
3️⃣ Database Isolation
Nice decoupling between:
This is clean.
⚠️ Where It Breaks Down
Now the serious architectural critique.
1️⃣ Your src Layer Is Mixing Layers
Right now:
This is horizontal grouping.
For GenAI systems, vertical slicing often scales better.
Example:
Instead of:
Prefer:
Because GenAI systems evolve feature-by-feature, not layer-by-layer.
2️⃣ No Explicit Service Layer
You have:
But I don’t see a service/application layer.
Example:
Where is:
If that is inside routers → ❌ architectural smell.
Routers should only:
Nothing more.
3️⃣ RAG Is Not Modeled Explicitly
In serious GenAI systems, RAG deserves its own domain:
Example:
Right now embeddings are inside llm/.
That mixes:
They are different layers.
4️⃣ Missing Explicit Domain Boundaries
You have:
But what is the system’s core domain?
If this is:
fintech document analysis
Your domain should be explicit:
Right now it’s infra-driven, not domain-driven.
5️⃣ Observability Is Too Thin
For GenAI production systems, you need:
retrieval metrics (recall@k, MRR)
Observability in GenAI is first-class — not optional.
🔥 What a Production-Grade Structure Would Look Like
Here’s what I would recommend for your level (enterprise GenAI builder):
Why this works better:
HTTP, CLI, background jobs
This scales cleanly.
🎯 Evaluation Summary
GenAI Architecture Correctness
The Core Question
If this is:
A serious GenAI product (like Finttics / HiNRI scale) → restructure now before technical debt compounds.
Given your pattern of building serious GenAI systems, I would refactor early.
Redesign this specifically for LLM-heavy RAG product
Good.
For an LLM-heavy RAG system, structure must reflect one truth:
RAG is not a utility — it is the architecture.
Your current layout treats LLM as a module.
In a serious RAG system, retrieval, ranking, grounding, evaluation, and observability are first-class citizens.
Below is a production-grade redesign optimized for:
Evaluation & observability
Future multi-agent extensibility
🔷 Target Architecture: LLM-Heavy RAG System
🔷 Why This Structure Works
Let’s go layer by layer.
1️⃣ Domain Layer (Business Logic Only)
This contains pure logic.
No:
Example:
Domain should express:
What is an answer with citations?
Nothing infrastructure-related.
2️⃣ Application Layer (Orchestration)
This is where RAG orchestration lives conceptually.
Example:
Application layer:
3️⃣ Infrastructure Layer (All External Systems)
This is where complexity belongs.
Handles:
Provider abstraction (OpenAI, Anthropic, Azure)
LLM is treated as:
External stateless inference dependency.
Separate from LLM chat.
Because:
Embeddings evolve differently
May use batch async pipelines
Since you’ve benchmarked FAISS, Qdrant, Milvus etc., you want:
Then:
Swappable.
RAG systems fail without reranking.
Keep cross-encoder or LLM-reranking isolated.
🔹 Observability
This must log:
RAG without observability is blind.
4️⃣ Dedicated rag/ Module
This is critical.
This module represents the architectural brain.
Vector search + filters
Cross-encoder ranking
🔹 context_builder.py
Chunk packing strategy:
🔹 prompt_builder.py
RAG-specific prompt templates
Calls LLM with final context
This separation gives you:
Swappable retrieval strategies
Future multi-agent expansion
🔷 Ingestion Architecture
For LLM-heavy RAG, ingestion is half the system.
Add:
Pipeline:
Documents are not simple files.
They are data pipelines.
🔷 RAG Flow (Execution View)
Here is how the system executes:
Clean.
Composable.
Testable.
🔷 Advanced Production Additions
For your level (given your LangGraph + enterprise focus), I’d also add:
And:
Because real RAG products must evolve experimentally.
🔥 Architectural Principles This Enforces
RAG is architecture, not function
Retrieval is infra, not utility
Observability is mandatory
🎯 If This Is Fintech Document RAG (like Finttics)
Add:
And add:
For:
answer confidence scoring
🔎 Maturity Comparison
Add multi-agent orchestration
Final Assessment
If you implement this:
Your system becomes extensible
Retrieval experiments become trivial
You can swap vector DBs easily
You can integrate LangGraph later
You avoid tech debt explosion