1. Bring a large pot of water to a boil. Add soba noodles to boiling water and cook for 4 to 5 minutes. Transfer noodles to a colander and run under cold water to cool. Drain well.
2. To make pesto: Place cilantro, parsley, almonds, garlic, edamame, pepper flakes, and salt in a food processor and pulse until incorporated (30 seconds). With motor running, drizzle in lime juice, oil, and water,and process until smooth (another 30 seconds), adding more water by the tablespoonful if necessary.
3. Transfer pesto to a large bowl. Add the noodles and cabbage to the bowl and toss until noodles are well coated. Divide noodle salad among 4 plates; sprinkle with feta.