Manual Alpha. Hybrid Beta. Automated Gamma.
From day one and throughout your alpha phase, what you really want to try and learn is:
1. Do people really want to do this?
2. How are they willing to do it?
3. How frequently are they willing to do it?
4. How much value do they get out of it?
5. What kind of value is it? (emotional, physical, financial, time saving, etc.)
Even though I'm a software developer and technology guy at heart, more often than not, I think almost all of the above can be learned from a (mostly) manual process of interacting with a small set of hand selected alpha users (who are your target customer).
Though cumbersome and time consuming at first, it will help you.
1. Discover what your target user really values (and expects).
Beyond idea and market validation (which is the primary goal here), it should also help you really suss out the true product plan (and in what priority order everything must be put together).
2. Keep launch costs tiny (if not free).
The real initial investment here should mostly be time (pro tip #6. Spend time before money when starting, then money before time when scaling).
3. Determine a clear path to what needs built and in what order.
Strongly related to point #1, by manually running the service yourself you'll quickly identify the highest client-value tasks, and start to automate or delegate the ones that are the most time & energy drains for you (working through the list until you've replaced all the hardest/highest cost manual labor, bit-by-bit)
4. Avoid initial and early technical debt.
It will help you make less assumptions and more data-driven decisions as you actually make your technology choices and start to build the real software.
Now all that being said - as I mentioned, I'm a software developer at heart - so while I'm *really* good at advising other founders, my portfolio companies, and my potential investments around this topic (sometimes even turning down lucrative freelance projects b/c aren’t actually ready to build IMHO)...I also actually struggle with this in practice (building the software is my comfort zone).
And sometimes you really do have to build at least some software before people can experience any part of your vision (e.g. I had to have a way for you to actually save, view, and share links before I could try and get any alpha users for Half Bite -- and I couldn't think of any manual ways of doing those things that would truly mimic the user experience I wanted to test for and learn from).
So, I guess like any advice I give, just apply what makes sense to you and your specific situation (and ignore the rest).