I would say the answer depends on Where in Europe your friends are seeking employment. The job market - and the job requirements - are significantly different between Rural Romania, Berlin or an oil field in Norway.
They are 30+. General advice there is to stay away from competing with the 20+ crowd. Compete where age is on your side, which means go into business where you have 10 years experience over the young ones. If you were a carpenter and want to be a programmer, build solutions for the construction industry. If you were a car mechanic, build solutions for the car salesman. You get the idea.
For starters, your friends can choose between getting an education , or trying their luck at "skill". If they want to work for big corporations, education is mandatory. If they want to work for small companies, education isn't going to be as important, but reputation is key. Be sure to never leave a job unfinished, and always ensure your customer is happy. Your happy customers are your salespeople.
If one of your friends are already fluent in HTML/CSS, it's natural to go into the custom wordpress theme coding, etc. This is not really an IT job anymore, but a part of the advertising industry. Pays poorly, and will continue downwards.
Your DSP friend is in better luck. This is a hard, difficult-to-learn skill. Especially if he also understands the advanced math behind it. Good DSP jobs are found in larger industries, so if he doesn't have a math degree, that would be advised. Having a Master's degree and being good at DSP programming will secure a very good future with few competitors.
As for "programming", that's not really one job but a wide field of jobs. Marketing style jobs are plenty and small, and available for both web and mobile. They pay poorly though. Corporate 10000+ hour projects or salaried positions are out there, but almost always require a M Sc.
There are always going to be plenty of 100 hour projects at smaller companies, but it's poor job security.
"Programming" in general is also under very heavy fire from outsourcing to lowest bidder, so I would not advise anyone to start it as a career.
YMMV.