It's very hard to pass this analysis, since "high tech" is almost universally more valuable to humanity, per unit, that something low tech like farming.
If you're already in tech and you want to "help the world", giving money is almost always the best choice.
http://www.givewell.org/ is a good resource for where to give effectively.
> but the typical conclusion would be "effective altruism indicates I should stay in tech and give money to helping fisherman transition to seaweed farming."
Don't make assumptions. Life is meant to be enjoyed, and we work for a third of our lives. Perhaps some of us don't want to do the same work for our entire lives.
Lastly, tech isn't how I would give altruistically. I'd trade options and futures and donate the profits. The impact would be orders of magnitude higher than donating my hourly/salary wages.
In amongst those tenets is the precept of comparative wealth, quoted here:
> Many effective altruists believe that, as formulated by Peter Singer, "if it is in our power to prevent something bad from happening, without thereby sacrificing anything of comparable moral importance, we ought, morally, to do it".[18] Anyone with an income of above $52,000 PPP is in the 1% richest people globally.[19] Therefore, many effective altruists donate a significant portion of their income to highly effective charities, since doing so would not cause them to give up important purchases.
In short, if you're making six figures in tech, it is generally more charitable to keep doing the tech that you're doing and donate more, and if the tech work you're doing isn't a net negative, you'll be doing more good by donating your tech largesse to a seaweed farmer instead.
> effective altruism indicates I should stay in tech and give money to helping fisherman transition to seaweed farming
Offtopic, but since when did contextual assumption become something people weren't supposed to do?
Large scale farming is not low-tech. Presumably someone moving in to farming from a tech discipline would seek to optimise their tech use as a competitive advantage over incumbents.