2900 Euro spendable income is 90% of the average family income in Berlin (source in German). And your family's earning potential is higher than your starting salary, as you could hope for a raise, or your wife could also start working, at least part time.
You won't be able to have a very lavish lifestyle, in the sense that many people you see will have something you cannot afford, for example a new car. But before you get jealous, you have to remember that those people have given up something else you are spending money on to get that car. It is only the rich ones who can have all signs of affluence at once.
With that kind of money, you won't be starting at the bottom of the social ladder. You may not be able to afford everything you see advertised, and you will probably live in a flat smaller and further away from the center than you wish (rent is currently really expensive in Germany), but many people you interact with on a daily basis will be living on less.
So this money will take care of "standard" daily/monthly/yearly expenses. Do not forget to protect against emergencies, these are especially hard if you don't have a network of family and friends close by. The mandatory health insurance (deducted before you get your 2900/month) will take care of all medical emergencies without any noticeable copayment. But you should get at least a Haftpflichtversicherung, which pays for damage you happen to inflict on other people's health or property (e.g. your washing machine breaks and floods the neighbour below you and you have to pay 20 000 for repairs). And, in your situation as a single breadwinner, seriously consider a good Berufsunfähigkeitsversicherung, it pays you a monthly income if you get disabled by disease or accident and can no longer work. You may hear that they are expensive, but the price varies by your occupation, and people who write software pay a comparatively low premium.