1. A week before their joining, we ship the laptop
2. I'd have a calendar ready for them, which gives an overview of what they will be doing for the next three months
3. First week goes into setting up the tooling on the machine. Someone from the product team gives an overview and entire product walkthrough. Next, they spend some to play with the product as a user. This week also involves the initial orientation session.
4. We use Golang heavily, however, the people joining might not know it. The second week goes into doing the tour of go.
5. Third week they spend on onboarding tutorial that shows how to write a small service, generate APIs, build, and deploy it in our infra.
6. Fourth week they will spend shipping a really small feature to the production.
7. Since day one, they'd have assigned a buddy who becomes their go-to person. Buddy also explains them about the culture, how things typical done here etc.
8. First three months, they'd spend working on a feature along with someone which also involves some good amount of pair programming.
(I am not a manager or a team lead, but trying to fix the issues which I have seen in the onboarding)