Programming is a trainable pursuit. Perhaps they are mediocre, or perhaps they are even bad. So, the best thing you can do is spend a significant portion of the time pair programming and seeing the project through their eyes.
Second, you probably should be taking some of that time you are coding and instead extensively documenting how it works, the design methodology, and making sure the unit tests are covering the code. After all, there are many implicit decisions in the code that they have to re-discover.
If you don't have tests, it makes working on a project as a new engineer difficult because you have no guard rails to know if something broke, especially because the specification is only in your head.
If you invest in your other engineers and in the process, they will become much faster and that slow down is a temporary bump in the road.
Second, you probably should be taking some of that time you are coding and instead extensively documenting how it works, the design methodology, and making sure the unit tests are covering the code. After all, there are many implicit decisions in the code that they have to re-discover.
If you don't have tests, it makes working on a project as a new engineer difficult because you have no guard rails to know if something broke, especially because the specification is only in your head.
If you invest in your other engineers and in the process, they will become much faster and that slow down is a temporary bump in the road.