Cook all of your own meals. Don't buy drinks at the bars if you go out. Don't buy expensive shit, you don't need the newest iphone every year or name brand designer stuff. Get a roommate. Not rocket sciene
If you can get very efficient at it or you find the activity a source of leisure, then cooking your own food is a great cost savings. However, for someone in the tech industry the opportunity cost of not investing in themselves (i.e. coding, reading about code, meeting people, etc) for the same amount of time they are cooking (grocery shopping, food prep, cooking, cleaning, etc) usually isn't worth it.
To me cooking your own food seems like a penny-wise, pound foolish thing. Of course eating out healthily multiple times a day gets insanely expensive, so that's not really an option either. That's why I'm a big advocate of soylent.
Most meals aren't actually a huge time investment if you do them right. Make one trip to the grocery store a week (or two if you really need perishables like milk or fresh fish, but if you do that, just go in & out with a list). Make sure your apartment has a dishwasher. Get a (dishwasher-safe) food processor for chopping & dicing. Clean up while the food is cooking in the oven or on the stove. Cook big batches and have leftovers during the week.
My wife and I spend maybe 3-4 hours/week on cooking, but the key is that it's usually all batched up on Sunday (and maybe Wednesday) nights, so it doesn't interfere with work during the week. On weekdays, it takes 2 minutes to pop a tupperware into the microwave and dump it onto a plate. That's actually a lot faster than ordering Munchery or preparing Blue Apron.
In that vein, a friend once calculated whether the time saved by not brushing his teeth would be offset by the cost of dentist visits later.
I don't remember the conclusion, but after I reminded him that female attention would likely drop off in proportion to bad breath, he decided against testing the idea.
Seriously man, it's food. We all have to eat, what is so important that you can't give up a couple hours a week towards cooking good food and leisurely eating it. Your entire life doesn't have to revolve around the almighty Opportunity Cost.
However, for someone in the tech industry the opportunity cost of not investing
in themselves (i.e. coding, reading about code, meeting people, etc)
for the same amount of time they are cooking (grocery shopping, food prep, cooking,
cleaning, etc) usually isn't worth it.
I would argue that the time spent away from the technical side doing other things is a bigger investment in self than a few extra hours a week writing code.
It's an efficiency tool. Does every single one of your meals have to be "the best meal ever" where everything is made from scratch from ingredients you sourced yourself from the farmer's market? Of course not. There are definitely times where you don't care to enjoy your meal and just need some nutritional sustenance. Traditionally in those cases your options were fast food, or maybe some kind of protein bar. Soylent is a better alternative in my mind to those.
One pleasant side effect of the "blandness" is that it has made me really enjoy the meals that I do eat. I've noticed that the flavors pop a lot more. So now I have the best of both worlds.
It would be wrong to write off cooking as an opportunity cost of not investing in yourself. First, you have the opportunity to put high quality food into yourself. Second, the tasks of recipe creation and cooking are very, very similar to software creation tasks. You start with a language (raw ingredients, characters) and combine them into your final product.
Rent first: maybe SF doesn't have any places with cheap rent, but the South Bay does. There are outliers in the market: $800/mo for a room or $1200/mo for a studio.
Car second: if you get an old car then the repairs + depreciation can be ~$500 / yr.
Services third: look at your most expensive purchases (Are there things that could be bought cheaper?) and your monthly bills (Do I need Netflix and Comcast cable? Do I need Costco and Amazon Prime? Do I need that EC2 instance? Do I need the deluxe laundry service?).
Food fourth: budget $5-$20 / day, leverage free food from your employer if possible.
Also don't get sucked into living an expensive lifestyle when you get that high-paying job--this has killed many people's once-promising futures.