It's not your imagination - these types of calls are out of control. According to our data, 40% of all calls made in the US are illegal, unwanted spam/scam robocalls. And those "neighbor" spoofed calls (same area code and extension) are especially prevalent now. Beginning last summer, they started to account for ~20% of all robocalls. Before that they were only about 2% of all robocall volume.
The Do Not Call list is almost completely ineffective against these types of calls. It was created 15+ years ago to stop legitimate companies from telemarketing. But today's robocallers are criminals that don't really care about the law. They have one goal - scam people and take their money.
Manually blocking calls will also get you nowhere. And please, for the love of god, don't press a number to get on their alleged "do-not-call" list. That will guarantee that you will get even more robocalls - they know you're a live number now.
On the technical side, our landline service (free) is powered by Twilio and our mobile product is available in both app stores (14 day free trial, $2 bucks a month after that). We're a PHP/Laravel shop and our team is completely remote.
To do the actual detection, our algorithm analyzes over 70M calls per month and adds over 1,300 new numbers to the blacklist every day. We built the world's largest commercial telephony honeypot (300k+ lines) and can detect new attacks within minutes of them starting (even with spoofed numbers). Just last month, Nomorobo stopped over 27 million from reaching people's phones.
I'm happy to answer any other questions that you have about robocalls. I'm kind of the "robocall guy". I won the FTC Robocall challenge back in 2013 and grew Nomorobo to be the leading robocall blocker on the market. I've even testified in front of the US Senate about the robocall epidemic.