An Americano is made by combining espresso with water after extraction. This creates a larger, less concentrated drink while retaining the espresso as a distinct preparation step. Café serving sizes and shot counts differ, so the name alone does not tell you how much coffee or water will be in the cup.
Start with an espresso recipe you enjoy. Add a measured amount of hot water, taste, and increase it gradually until the concentration suits you. Using water first and pouring espresso on top gives a long-black-style presentation and may leave more visible crema. Neither assembly order replaces tasting, and the amount of foam is not a complete test of coffee quality.
Running more water through the same puck is a different brewing choice from adding water to the finished shot. A lungo can be approached as its own recipe rather than automatically described as badly made espresso. For a useful comparison, record dose, espresso yield and added water separately. A short concentrated shot, a longer shot and a diluted finished shot can then be judged on their actual recipes, instead of assumptions attached to drink names or serving size.
The conversation
A good question can make a better brew.