Combine shrimp, garlic, and 2 Tbsp olive oil in a small bowl and let marinate for 20 minutes.
Using a spiralizer or mandolin, create long strips of zucchini that resemble spaghetti noodles.
When the shrimp is done marinating, add the shrimp mixture to a large skillet over medium heat. Cook for about 5 minutes, until shrimp is cooked through. Remove from pan and set aside.
Add the remaining olive oil to the pan, along with the zucchini noodles. Cook over medium heat for about 10 minutes.
Add the pesto and lemon juice to the noodles and toss to combine. Cook for an additional 5 minutes or until the noodles are tender.
Add shrimp back into the pan and combine with the noodles to warm. Salt and pepper to taste.
Garnish with lemon zest and serve.