As an IRL Programmer / Sysadmin / SRE / Bioengineer / Bioinformaticist, multiclassing (and taking dual-progression PRCs) feels natural to me. On one recent adventure, I was serving as the party's programmer, statistician and UX designer when we discovered we were short an oncologist. So I dipped a tenth of a level in oncologist. No big deal.

A friend of mine who was an Artificier / Bard dipped Cleric so he could officiate a wedding. No big deal.

Each level represents the skills you focused on developing on that occasion. There's no need to have a plan that ends in enlightenment, and no reasonable expectation that such a plan would survive contact with reality.

(Some classes may be unreasonably front-loaded, especially if weapons proficiencies are important. 5e's special multiclassing rules may be useful here.)