In a large salad bowl bowl, combine 2 tbsp of lime juice and 1/8 tsp salt. Add the diced cucumbers and toss them in the mixture. Let this sit while you prep/measure the other ingredients. It will taste tart, but don't worry! This will dilute when you mix this together with the other ingredients.
Once you have measured all of your ingredients, set aside some pumpkin seeds, goat cheese, shallots, cilantro and mint for topping. Just about 1 tbsp of each ingredient.
Add the watermelon, pumpkin seeds, shallots, cilantro, mint, and half of the goat cheese to the bowl with the cucumbers. Sprinkle a little more salt and 2 more tsp of lime juice to taste and then toss until combined.
Taste to make sure the lime and salt levels are to your liking. If you want more lime, add more lime juice! If you want more salt, sprinkle 1/8 tsp at a time and continue to taste until your salty needs are met.
Serve on a platter and top with the reserved ingredients. Enjoy immediately! This will get soggy in the fridge. If you want to make ahead, you can prep the ingredients ahead of time. Make sure you are tossing them together right before serving.