Most (if not all) generic onboarding methodologies are recipes for failure. Why do you hire a new person? Because a) the people you already have are insufficient b) they are sufficient but you are constrained by time/space in some way such that they cannot meet demand c) you do not have any people who do X (some technical skill). All three of these are important but they are, in fact, secondary to the current and reasonably identifiable future states of the entity.

Most canned technical onboarding systems are misaligned with organizational strengths/weaknesses and the overall technological roadmap that, to be effective, should be at least influenced by the company's industry. So if you work at an auto parts recycling business and your competitors are not investing in technology but instead in storage capacity for instance a heavy investment in technology at this time is likely the incorrect decision. You want to lower maintenance costs and focus on system stability/so-called future-proofing instead of new development. Hence, you hire someone well versed in doing just that with your existing systems.

The problem with onboarding is that it relies too heavily on technological people who do not spend enough time talking to other parts of the business to assess what is really needed today AND tomorrow. They like Java so they hire Java developers because they make them feel 'comfortable' without asking what phase their business and its industry is in -- growth, stability, or decline. High growth businesses need systems fast and your environment should be able to reduce critical errors while absorbing/minimizing the impact of minor ones. You'll need agile developers with modern programming skills and short memories. Here the emphasis is on speed -- you want to gain the foothold on whatever market you are moving into. This is a different focus than a large, established/stable market. If you hire the aforementioned developers in this case they will become dissatisfied and will try to push for new development when it is not the the business' best interests. In a declining market you need to focus on survival -- elimination of the highest costing lowest benefit producing systems for lower cost alternatives. Cut, cut, cut to the nub. People with heavy emotional ties to doing things in a certain way will find themselves on the out in this case.

So you see, hiring and onboarding must take a back seat to where the business is and where it is going. Once you have clarity in this regard how much/little you need to do things like onboarding become rudimentary.