The insane tracking shot brawl in "Atomic Blonde" took four days to shoot, and only happened because John Wick director David Leitch was willing to give stuntmen opportunities as actors.

Who doesn’t love a good action movie about revenge? What Liam Neeson did in 2008 with “Taken” has allowed it to become one of the most influential Hollywood films of the last decade or so.  You know the formula by now: an aging male superstar plays a former intelligence agent or operative or assassin, with a “particular set of skills,” who comes out of retirement after a close relative is murdered or kidnapped. Of course that “close relative” has evolved over the years to become a spouse, a daughter, a friend, or even, in the case of “John Wick,” a pet. Then our washed up,  former bad boy ends up systematically hunting down and killing a bunch of foreign baddies.

Neeson and “Taken” really started a chain reaction of older, more mature-looking, Hollywood A-listers taking a crack at being action stars. Just look at the list of similar revenge action vehicles that came next: Keanu Reeves in “John Wick,” Denzel Washington in “The Equalizer,” Sean Penn in “The Gunman,” Kevin Costner in “3 Days to Kill,” and Pierce Brosnan in “The November Man.” Neeson has himself become a one-man genre, not only were there two other “Taken” movies, but he’s also done ‘Taken’-esque films like “A Walk Among the Tombstones,” “Run All Night,” “Non-Stop,” and “Unknown.” All starring male actors, but how about the women? 
I thought "Atomic Blonde" was worth a watch just for its elaborately conceived fight scenes. I mean, these were just jaw-dropping sequences that almost made up for the dull plot. Charlize Theron starred as Lorraine Broughton, the titular atomic blonde, an MI6 agent that also happens to have a special set of skills, hell, she'll even turn a household item into a lethal weapon. 

The piece de resistance of the film, and there are plenty of contenders, takes place in an East Berlin apartment building, where Lorraine takes on a squad of KGB agents. Director David Leitch is an incredible new talent in Hollywood, he was intially a stunt coordinator for 20 years before making his directorial debut with "John Wick," and in that movie you could sense the years of experience in stunt-making business paying off.  He has mentioned the apartment sequence was  “the pinnacle of the action in the movie,” 

The aforementioned sequence begins in the middle of a political protest which leads our characters to an empty apartment building with four extended staircases connecting three floors. The scene has Lorraine in charge of protecting the life of a defecting Stasi officer. The beating Theron's Lorraine takes here is punishing to watch, the actors she faces off against were trained professionals and I wouldn't be surprised if she had more than a few bruises by the end of the shoot. It’s clear that Leitch’s experienced eye for detail helped here, resulting in some of the most intense and complicated fight scene in recent studio cinema history.

What's more astonishing is that it seems to be done in what appears to be (but isn't) a single take. How did Leitch pull this off? Here he is speaking to Rolling Stone:

"I wanted to do something that was really provocative and shocking to the audience. So the idea was to stay with the character and really feel immersed in the action – to feel every punch and [all of] her fear. Basically, we wanted to not give the audience a chance to take a breath. Psychologically, with the illusion of a single take ... you're always waiting for the cut. The edit makes you feel like you're in a movie. So when you're not seeing them, your mind goes to a different place."
"Logistically, it's probably assembling 20-plus shots. That being said, for those nine minutes of screen time ... there are some really long pieces of choreography that involved coordination with stunts, special effects and actors. Everyone had to be on their game to get these long takes that were, like, over a minute long. If you messed up any beat in the middle, you had to start over. But it is assembling several takes. To do that, we used a lot of old-school camera tricks with whip-pans and lens-crafting, using frames to create split-screens. It's not as high-tech as you think; it's really a lot of clever, old-school filmmaking."
"The [single-take forest assault] sequence in Children of Men was something that always really fascinated me when I first saw it. I think the departure we wanted to take is that, in that movie, the action goes on around a protagonist. What I wanted to do was, 'Okay, she is sort of the trigger point of the action.' So instead of watching explosions in the background and a war going on – she is the war going on. It's going to feel physically exhausting, and also more unbelievable that you were able to keep the camera rolling for that long."
"What's great about Charlize is, when I said, 'I want to make this special,' the way to do it is to dive into the training:  do your own choreography and stunts. Never break character and never break the illusion in using the convention of the stunt double, or the over-the-shoulder shot of the stunt double and just your close-up. We need to see you do it in wide shots and long pieces. I threw down the gauntlet early, but she snatched it up willingly. She gave it 110%. Once she understood what we wanted to do, she was all over it."

[Rolling Stone]