backend/Dockerfile

@@ -1,28 +1,45 @@
-# syntax=docker/dockerfile:1.4
-# Multi-stage build for FastAPI backend with optimized caching
+# Multi-stage build for FastAPI backend - Railway optimized
+# Optimization: Split dependencies into stable base + app layers for better cache hits
 
 FROM python:3.11-slim as builder
 
-# Set working directory
 WORKDIR /app
 
-# Install system dependencies (cached layer)
+# Install system dependencies (cached layer - rarely changes)
 RUN apt-get update && apt-get install -y --no-install-recommends \
     build-essential \
     git \
     && rm -rf /var/lib/apt/lists/*
 
-# Upgrade pip once (cached layer)
+# Upgrade pip (cached layer)
 RUN pip install --no-cache-dir --upgrade pip
 
-# Copy ONLY requirements first for better layer caching
-# This layer only rebuilds when requirements.txt changes
-COPY backend/requirements.txt .
+# OPTIMIZATION: Install heavy/stable dependencies first (better layer caching)
+# These packages rarely change and take longest to install
+RUN pip install --no-cache-dir --prefer-binary \
+    torch --index-url https://download.pytorch.org/whl/cpu || true
 
-# Install Python dependencies with BuildKit cache mount
-# This caches downloaded packages between builds, dramatically speeding up rebuilds
-RUN --mount=type=cache,id=pip-cache,target=/root/.cache/pip \
-    pip install --prefer-binary -r requirements.txt
+# Install ML/NLP packages that are large but stable
+RUN pip install --no-cache-dir --prefer-binary \
+    sentence-transformers \
+    chromadb \
+    langchain-openai \
+    langchain-experimental \
+    langchain_anthropic \
+    langchain-google-genai \
+    langgraph
+
+# Install data processing packages
+RUN pip install --no-cache-dir --prefer-binary \
+    polars \
+    pyarrow \
+    pandas \
+    numpy \
+    matplotlib
+
+# Copy and install remaining requirements
+COPY backend/requirements.txt .
+RUN pip install --no-cache-dir --prefer-binary -r requirements.txt
 
 # Production stage
 FROM python:3.11-slim
@@ -33,7 +50,7 @@ WORKDIR /app
 COPY --from=builder /usr/local/lib/python3.11/site-packages /usr/local/lib/python3.11/site-packages
 COPY --from=builder /usr/local/bin /usr/local/bin
 
-# Copy application code from backend directory (including __main__.py for python -m)
+# Copy application code from backend directory
 COPY backend ./backend
 
 # Copy tradingagents package from project root
@@ -49,5 +66,5 @@ RUN mkdir -p /app/results
 EXPOSE 8000
 
 # Run the application using the PORT environment variable (required by Railway)
-# Using --reload false to prevent hot-reload issues in production
 CMD ["sh", "-c", "python -m backend --reload false --port ${PORT:-8000}"]
+