Heat your pot to medium. Add sausage and crumble with a spatula, cooking until browned and no longer pink. Remove from pot and set aside.
Add celery, onion, carrots, salt, pepper, and chili flakes (if using). Cook for 8-10 minutes, stirring occasionally, until the onions are translucent and vegetables begin to soften.
Add garlic and stir. Cook for 1-2 minutes, stirring frequently, until just fragrant.
Add back cooked sausage crumbles with zucchini, potato, green beans, beans, crushed tomatoes, broth, bay leaves, and parmesan rind. Stir and cover, keeping the heat to medium until the soup reaches a gentle boil. Then, turn it to medium low and simmer, covered, for 30-45 minutes or until potatoes are soft.
Add pasta and stir. Continue to simmer for 7-10 minutes or until pasta is cooked to al dente.
Remove the bay leaves and parmesan rind when your pasta is done cooking, and turn off the heat. Serve and enjoy!