However, it looks like the numbers are pretty comparable. In Germany a software engineer will average 47,500[0] euros a year. judging by this answer[1] I'm guessing your take home is going to be about 28,000 euros (2,333 euros a month), meaning about a 40% tax rate.
According to the same website a software engineer in Zurich will make 96,500[2] CHF. Using a swiss salary calculator, your take home in euros is 71,436[3] (5,953 euros a month).
Finally, comparing the cost of living, is clear to see that Germany is 50% cheaper[4], but you're making 150% more in Zurich. While my numbers may be the wrong averages to compare, it looks like Zurich is at least pretty comparable.
[0] http://www.payscale.com/research/DE/Job=Software_Engineer/Sa...
[1] https://www.quora.com/Is-45000-euros-per-year-considered-a-g...
[2] http://www.payscale.com/research/CH/Job=Software_Engineer/Sa...
[3] http://www.lohncomputer.ch/en/home.html
[4] http://www.numbeo.com/cost-of-living/compare_cities.jsp?coun...
96,500CHF is also a fairly conservative estimate. If you work at e.g. Google, you can reasonably expect twice that amount after 2-3 years working there (factoring in bonuses and stock). The tax rate is also lower compared to Germany, especially when you reach larger sums of money.
In Zurich you're netting three times what a German software engineer makes, but everything is only twice as expensive.
The landlady did keep my deposit (sorry, "had a professional cleaning done for the exact amount of the deposit", and sent me the detailed list as proof in German which I do not speak), bringing that to 2,250 CHF/month. A quick back of the envelope on real estate inflation since then brings me to around 2,500 CHF/month (1,700 CHF/month if you ignore the deposit trick).
That's not as cheap as a small town in Europe but it's quite cheap, I think, for a major international city and definitely when you take into account the starting salaries. Vaguely remembering, a graduate from a good university starting in strategy consulting could expect 90-110,000 CHF/year in Zurich vs 35,000 GBP (49,000 CHF) in London despite higher COL and higher taxes (same companies, which may or may not start with M or B). I have no idea about the numbers in San Francisco but I bet they are not so good either.
There's other issues with working in Switzerland if you come from Anglo-Saxon big cities, but COL isn't it if you are paid locally, unless you are dealing with an employer exploiting the unemployment rate in your home country to underpay you substantially (which is definitely the case with some French speaking companies in Geneva).
A friend of mine tried to keep their deposit by cleaning it themselves ("took two days and was spotless"). Because the landlady had not got a note from a cleaning firm saying it was clean, she literally could not rent it out again. And so charged my friend for the cleaning firm to come in. They did do a better job :-)
If the landlord fails to protect your deposit, and does so in what might be considered bad faith, a court will often order them to pay you 3x the deposit as compensation - so they all end up actually doing it.
I think something similar exists in Switzerland, but the (German) landlady correctly guessed that as a non-German-speaking foreigner, I would not take the time and expense to attempt it. Imagine attempting to contest the necessity of "dusting the sides of books on bookshelves" to an arbitrator in a foreign language...
[1] "For a tourist claim, the Tribunals may fix both the consultation/mediation and the hearing within 24 hours of filing of the claim." - https://www.statecourts.gov.sg/SmallClaims/Pages/GeneralInfo...
The city itself is tiny and the "city center" is even tinier. This leads to the variance of the rent being very high: In the very center of town you might have to pay 1500 CHF for a 1-bedroom apartment, but if you can live also 5 km from the city center, you can have it way cheaper.
I am renting a 4-bedroom apartment for 1600 CHF (https://flatfox.ch/de/wohnung/8051-zurich-grosswiesenstrasse...) and I need around 12 minutes to get to Zurich main train station.
To downvoters: please see my comment below. I am not against foreigners.
That's cheap compared to London (zone 1).