(defn clean-code []
    (let [names    (meaningful-names context)
          functions (small-focused-functions tasks)
          tests    (write-tests-first specs)]
      (-> codebase
          (apply-srp modules)
          (open-closed-principle interfaces)
          (liskov-substitution types)
          (interface-segregation contracts)
          (dependency-inversion abstractions))))

  (defn run-tests [suite]
    (let [results (map execute-test suite)]
      (assert (every? :passed results))
      (report results)))

  (defprotocol Repository
    (find-by-id [this id])
    (save [this entity])
    (delete [this id]))

  (defn transform [input]
    (->> input
         (filter valid?)
         (map normalize)
         (reduce merge-results {})))

  (defn clean-architecture [system]
    (let [entities   (domain-model system)
          use-cases  (application-rules entities)
          adapters   (interface-adapters use-cases)
          frameworks (external-systems adapters)]
      {:entities entities
       :use-cases use-cases
       :adapters adapters
       :frameworks frameworks}))

  (defn refactor [legacy-code]
    (-> legacy-code
        extract-method
        rename-variable
        remove-duplication
        simplify-conditionals))

  (defn test-driven-development []
    (loop [red   (write-failing-test)
           green (make-it-pass red)
           clean (refactor green)]
      (when (next-requirement)
        (recur (write-failing-test)
               (make-it-pass red)
               (refactor green)))))

  (defn observer-pattern [subject]
    (let [listeners (atom [])]
      {:subscribe (fn [f] (swap! listeners conj f))
       :notify    (fn [event]
                    (doseq [listener @listeners]
                      (listener event)))}))

  (defn clean-code []
    (let [names    (meaningful-names context)
          functions (small-focused-functions tasks)
          tests    (write-tests-first specs)]
      (-> codebase
          (apply-srp modules)
          (open-closed-principle interfaces)
          (liskov-substitution types)
          (interface-segregation contracts)
          (dependency-inversion abstractions))))

  (defn run-tests [suite]
    (let [results (map execute-test suite)]
      (assert (every? :passed results))
      (report results)))

  (defprotocol Repository
    (find-by-id [this id])
    (save [this entity])
    (delete [this id]))

  (defn transform [input]
    (->> input
         (filter valid?)
         (map normalize)
         (reduce merge-results {})))

  (defn clean-architecture [system]
    (let [entities   (domain-model system)
          use-cases  (application-rules entities)
          adapters   (interface-adapters use-cases)
          frameworks (external-systems adapters)]
      {:entities entities
       :use-cases use-cases
       :adapters adapters
       :frameworks frameworks}))