Deployment — Document Summarizer

Docker

FROM python:3.11-slim
WORKDIR /app
RUN apt-get update && apt-get install -y --no-install-recommends \
    libmupdf-dev \
    && rm -rf /var/lib/apt/lists/*
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt
COPY . .
EXPOSE 8000
CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--port", "8000"]

PyMuPDF requires system libraries

The libmupdf-dev apt package is needed for PyMuPDF (fitz) to compile. If you see ImportError: libmupdf.so not found, this is the fix.

Fly.io

# fly.toml
app = 'document-summarizer'
primary_region = 'iad'

[build]
  dockerfile = 'Dockerfile'

[http_service]
  internal_port = 8000
  force_https = true
  auto_stop_machines = true
  auto_start_machines = true
  min_machines_running = 0

[[vm]]
  memory = "1gb"
  cpu_kind = "shared"
  cpus = 1

flyctl launch --name document-summarizer
flyctl secrets set OPENAI_API_KEY=sk-...
flyctl deploy

File upload size limits

Fly.io and most platforms have request body limits. Set the limit in FastAPI:

from fastapi import FastAPI
from starlette.middleware.trustedhost import TrustedHostMiddleware

app = FastAPI()

# Increase upload limit to 10MB
from starlette.datastructures import UploadFile as StarletteUploadFile
StarletteUploadFile.spool_max_size = 10 * 1024 * 1024

For nginx (if using a reverse proxy), add to the server block:

client_max_body_size 10M;

Request timeout tuning

Large documents take longer. Set appropriate timeouts:

# For a 50-page PDF with 10 chunks:
# map step: 10 concurrent calls × ~1s each = ~1-2s
# reduce step: ~1s
# Total: 3-5s

# Set FastAPI response timeout accordingly
CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--port", "8000", "--timeout-keep-alive", "30"]

---

04-evaluation | 06-interview-questions