eCommerce market is highly competitive and site speed plays a major role in improving overall buying experience and fulfilling user needs. In most companies there is always a constant push and pull towards spending time adding new features vs improving performance. There are also constraints around 3rd party integrations, ads & making changes happen across various teams can also be a challenge. In this talk we're going to look into ways by which you can smartly improve performance without cutting down on features and without changing much of the user's experience. We'll talk about different modern techniques that helped improve Walmart.com's speed and how understanding user behavior can go a long way in optimizing performance.