And as you would be building the container image again and again during development to check that your code changes are working, there's a lot of accumulated time this would save.

Then, near the end of the `Dockerfile`, we copy all the code. As this is what **changes most frequently**, we put it near the end, because almost always, anything after this step will not be able to use the cache.

```Dockerfile

* <a href="https://github.com/tiangolo/uvicorn-gunicorn-fastapi-docker" class="external-link" target="_blank">tiangolo/uvicorn-gunicorn-fastapi</a>.

!!! warning
    Existe uma grande chance de que você **não** precise dessa imagem base ou de qualquer outra semelhante, e seria melhor construir a imagem do zero, como [descrito acima em: Construa uma Imagem Docker para o FastAPI](#construindo-uma-imagem-docker-para-fastapi).