Everything you need to know about love you can find in Black Mirror's Hang the DJ

Hang the DJ is not about Internet dating.

What happened at the end of Hang the Dj Black Mirror

So what happened in Hang The DJ: (spoilers!!!!)

Amy and Frank meet in the first minute of the episode, enveloped by a curved couch they sit down for a date. They push trough the awkward first moments, acknowledge it, joke about it. Soon things are going well, but when they check their devices, an Echo formed gadget that guides them through this process of finding their perfect match, called The System, they are disappointed to see that their encounter will be a very brief one.
In a strange looking bus they head to a cabin, a very luxurious cabin, where the bed takes up the main part of the inside. They get the picture but they only hold hands that night. The next day they reluctantly and a bit shell shocked say goodbye. Immediately they are alerted of a new match.
Their next relationship is longer for both, Amy gets to make out with a hot guy for eight months, but his excessive exhaling gets on her nerves, And Frank hates his date from the outset but if forced to stay with the dreadful girl for a year.
At a party celebrating a couple who has reached that milestone of finding the prefect match, they see each other and it's obvious they haven't forgotten about each other.
After breaking up with her mouth-breather, bridging the four months that Frank is still in a relationship, Amy goes through tons of one night stands, feeling detached, bored and dejected. So when they are both single at the end of the year and get matched up again, they agree to not look up their expiring date and let life takes its course.
They flirt, laugh, tease, open up to each other, and make love. But Frank falling deeper in love can't contain himself and while Amy is asleep he checks the expiry date. His face lights up when he sees the five years given to them. Suddenly the device starts recalculating, explaining to him that his action, having broken the promise not to look, changes everything and the timer runs down, till Frank realize he has to say goodbye to Amy that same day.
Through all of this we get a sense that Frank and Amy are in a The Lobster kind of environment, a place surrounded by a huge wall, outside a wilderness awaits, the great unknown. When they are together the fabrication of their reality starts to reveal itself. Also not being able to recall their own history before arriving in this place,  their mindset starts to shift.
But first Amy is livid that Frank has broken his promise and checked the expiry date, and walks away.
Soon after Amy receives the message that the System finally has found her perfect match. And gives her the opportunity of saying goodbye to one person before leaving this place permanently. Of course she chooses Frank and the moment they arrive at their familiar booth, and passionately start to kiss, they know what they have to do. Leave together. This is a test, she says, don't you feel like we know each other, that we have done this many times before?  As they walk away, a guard points a weapon at Amy, she reaches out, puts her hand against it and instead of being zapped the whole world around them pauses.
Outside they start climbing the very high wall. Halfway through the world dissolves. and they find themselves in a dark space surrounded by other Amy and Franks. As they start to ascend, their bodies dissolving, the device tells them that there have been 1000 simulations before, and only in two they didn't rebel. As they dissolve we are back in present time, Amy and Frank strangers looking at each other from across a bar, while the Smiths are playing, their apps on their phones buzzing that they found a match. They smile at each other and walk towards one another. It's a 99.8 match. The screen says.

What is it really about:
There were some articles that said that this episode doesn't understand online dating, talking about algorithm and all that nonsense. But Hang the DJ is not about dating at all. It is about what comes after. It's not about how you know? But how you do you make it work.
Black Mirror has always been about technology versus human. Mostly a bleak concept, warning us of the consequences of too much reliance, of losing our identity, of merging with IA, of no escape, of defeat, all those things that scares us about technology. But Black Mirror is based on rebellion, that is what to has been telling us all along. Choose freedom.
So even if Amy and Frank are slaves to this System, and Hang the DJ could be interpreted as warning against online dating, how detached it can makes us feel, how superficial it can be, the meaning of it lays in the last few moments.
Hang the DJ is not so much about choosing a partner, sure Amy and Frank seem compatible enough, but really, are they? Or do they make it work?
IRL being in a long term relationship it's not enough to feel comfortable with each other, not enough to be compatible. In Hang the DJ their 99.8 compatibility in the end is not based on any of that.
It's only based on their choice. Time and time again they choose to be together, screw the rest. And that is what makes them a perfect match. They are willing to go into an unknown world, be courageous, and see what will happen, with no way of knowing what will. And that is how a long lasting relationship is build, you make a choice, even if you have no idea if it's the right thing to do, or even if this was the most compatible person for you. There is no right person, you make the person you love the right one. And you keep making that choice again and again and again.