Bring a pot of water to a boil. Add the bitter melon and eggplant to the boiling water and return to a boil; cook at a boil for 2 minutes. Drain. Rinse with cold water to stop from cooking further.
Toss the bitter melon, eggplant, carrot, garlic, green chile peppers, and sweet onion in a large bowl; cover with plastic wrap and set aside.
Stir the water, vinegar, ginger, sugar, and salt together in a pot; bring to a boil until the sugar has dissolved completely. Set aside to cool completely. Pour the cooled vinegar mixture over the vegetables in the bowl, assuring the vegetables are completely submerged. Cover and refrigerate. Serve cold.