Because of the unique nature of how “Tramps” was made and what a special film it is, we’re devoting this week to celebrating many of the artists behind the scenes that made it possible with a series of interviews illuminating their work before its premiere on Netflix.

When Andrew Neel was preparing his narrative debut “King Kelly,” following a string of documentaries including “Darkon” and “Alice Neel,” he, like many other directors finding their footing, sought out the services of the casting director Susan Shopmaker. Regardless of the circumstances, finding a lead for “King Kelly” was never going to be easy, ‎requiring an actress who play an obnoxious camgirl who wouldn’t alienate an audience as her increasingly reckless ploys for attention grow into desperate cries for help.

“It’s an incredibly aggressive role and it was very hard to find the look and the personality in one place,” recalls Neel, who was looking for someone confident enough to offer up their body to strangers online yet deeply vulnerable at her core. “When you play some of those scenes as written, it was hard to cast that role because it had to be a lot of things at once.”

Shopmaker relishes such challenges, to go by a nearly 30-year career in casting, and it wasn’t long before she brought in Louisa Krause, the soulful young actress whose blonde hair and tangy verbal delivery could make for a mean Valley Girl, to read for the role. You could’ve tipped Neel over with a feather after he saw her audition.

“I remember Louisa Krause came in with a giant Subway sandwich and she did the entire thing with her iPhone in one hand and her Subway sandwich in the other,” says the filmmaker, who has not only returned to Shopmaker for his own directorial efforts such as “Goat,” but has worked with her on the films he’s produced through his production company SeeThink Films such as “Bluebird” and “Stand Clear of the Closing Doors.” “And I just remember sitting there as the director almost overwhelmed by Louisa, like there’s something going on here that I don’t know exactly what it is. I remember she walked out and Susan was like, ‘That’s your horse.’…She saw the idiosyncratic in Louisa, which is what I think makes actors great, and she’s able to see that kernel in an actor that will make them great when you put them in front of the camera.”

This is what Adam Leon was looking for when he set himself a similarly daunting task for “Tramps,” writing a romantic caper that, like its Golden Age Hollywood ancestors from the 1930s and ’40s, leaned heavily on the charisma of leads. Yet set during contemporary times on the hardscrabble streets of Queens, he needed a captivating couple who felt less than polished, or in his words, “character actors who were going to become [movie stars].” (Oh, and one needed to become semi-fluent in Polish.) For this, his producer Joshua Astrachan suggested Shopmaker, with whom he goes back to the trenches of the remarkably fertile New York independent film scene of the 1990s, who noted “She never stops doing that hungry work of finding that next actor.”

In the years since when indie films have too often been cast with actors based on their value to foreign territories rather than their fitness for the part, Shopmaker’s films have felt like a refreshing rebuke, showing a rare gift for uncovering something new in actors we know or unearthing actors we don’t who exude that indescribable magnetism we expect of stars, populating the early films of John Cameron Mitchell (“Hedwig and the Angry Inch,” “Shortbus”) and joining the Borderline Films’ trio Antonio Campos (“Afterschool”), Sean Durkin (“Martha Marcy May Marlene”) and Josh Mond (“James White”) for their incredible run in recent years. Her willingness to take a chance on filmmakers at the start of their careers has also contributed immeasurably to the American independent film scene in more subtle ways, as she’s lent her credibility to daring productions where actors might feel uncomfortable taking chances on untested directors and both sides have reaped the benefits of bringing out the best in each other.

“Susan just has this absolutely unique energy,” says Leon. “And she’s hard, which is good. We needed to find gems and I knew that [Susan] was going to push hard to find them and push hard on us to make sure there was no settling going on, so I just really loved her spirit and her sensibility for the project.”

She did right by Leon, working closely with the director to find the right pair to play Danny and Ellie, strangers linked by a suitcase for which they’ll receive a $1500 payout if delivered to the right place amidst a sea of obstacles in the city, including a group of low-level thugs, in “Tramps.” With the film feeling as if it was shot on the run, Shopmaker helped narrow the search for actors who could handle the physical demands of the project, but were arresting in their own ways, bringing in an All-City high school basketball star in Grace Van Patten and Callum Turner, who has been known to play soccer in between booking gigs in such films as “Green Room” and “Assassin’s Creed.” Neither are obvious choices for their parts, with Van Patten having to cut off her flowing blond locks to play the short-haired brunette Ellie and the British-born Turner securing a job at a Polish hardware store (on his own volition) to pick up enough of the lingo to play Danny. But you’d never know it from watching the final film, where individually, they’re compelling separate from the roles they’re playing (as is almost always the case in Shopmaker’s films), but together they’re spellbinding.

Recently, Shopmaker took the time to talk about her process and her work on “Tramps,” in particular, reflecting on casting Van Patten and Turner, as well as Michal Vondel, who plays Danny’s wayward brother Darren, and how he not only got the part after some uncertainty, but brought along his mother to be in the film.

Adam Leon's "Tramps"Did you have immediate ideas when it came to this?

I probably did, and those people are not the leads in the movie. [laughs] It always takes some time to let it all settle. You have a script in one hand and the director in the other and sometimes they have a vision for the movie and the job is to meld those two when you’re casting. So probably my first ideas out the gate, certainly for [Ellie], were a darker version of who they ended up being. You see the auditions and basically, you say that’s the guy. There were other people who gave some lovely auditions, but they didn’t have both of those things – the innocence at the same time [as] also being sexy without understanding they had that.

You often work with filmmakers at the start of your careers – is that a different conversation than you have with veteran directors about what they want?

Specifically for “Tramps,” Adam knew a lot more about what he wanted than people would assume coming from a young director. He was pretty clear and they really did hire me to do a search for the two best people [for Danny and Ellie]. That was made very clear right upfront, so the discussions were only different in that I wasn’t making lists and lists of famous people, but that right out of the gate, we needed to see people through the work.

Adam said how much he appreciated how you scrutinized every decision not just in casting, but in terms of some of the story and character elements. Is that tough love approach is common practice for you?

It’s common practice for me, good or bad. [laughs] It doesn’t always work out so well. But the hope for all of us is you’re trying to make something and make it the best it can possibly be so sometimes your ego has to get checked at the door a little bit. It is hard to do these days, but [when] the idea is we’ve got to try to make the best film, if I’m casting on the page, [I ask] why is it on the page and if that’s what I’m looking for, then I need to go look for that. A little bit of it is starting to understand the difference between the story that I think is being told versus the story that the director is really trying to tell. But Adam was clear and that’s the best thing you can hope for. Sometimes directors don’t really know what they want and [there’s] not a lot of collaboration and I think Adam was excited to be in that room. He’s somebody who is going to have a conversation with you.

What was it like to find Callum?

We did a pretty wide search. For the role of Danny, the thing about Callum is that he’s a leading man without quite being a leading man, and you knew it the minute you saw him. He sent in a self-tape and it was just a remarkable performance in all ways. It was well thought out. It was clear. He understood the character. It was just all there, which sometimes isn’t the best thing [because] sometimes somebody brings it home instantly and then you have nowhere to go after that. But it was clear that he’s an actor. You could see the work and then [he and Adam] Skyped, and at a certain point, everyone agreed this is the guy.

Since he’s British, was it easy to see past that for him to play this Polish kid in Queens?

What did it is that for a lot of us who live in New York, [we see] a lot of these kids who grow up with a second language in their home who sometimes have these slightly odd accents to begin with, so at least personally speaking, we had a little bit of wiggle room. And it isn’t even that [Callum] spoke Polish so fluently because I don’t even think the character is supposed to. But there’s a slight strangeness. I live in a community that’s very mixed in New York, and the kids who are from here, their accents go in a few different directions when they’re talking to their parents [for instance], so it wasn’t that big a leap, at least for me.

If casting Callum came first, did that make it any easier to cast Grace as Ellie?

No. [laughs] It was easier once Grace came into the room, but it was interesting casting Ellie because you had to believe that she had this other life, yet when they were together you had to believe that they might fall in love. Some of the girls who came in didn’t have that softer quality.

Were there any scenes that you honed in on to see whether they could pull this off?

We used the same scenes for everybody, and there were other scenes, but one of them was the scene in a [restaurant] and they’re talking about [Rebecca Vargas] the girl [Danny] went to high school with — the testing the Tina scene, as I like to call it — where she has to have the upper hand, but at the same time, there’s an inkling that she finds him absolutely charming in his gawkiness.

Is it true you like to interview before reading them?

I don’t know that I do that so specifically, but I think by American standards we give people an awful long time in our office because we see so many young people. We really do the work first — you do the scene and then we talk to them [to] get a sense of who someone is, even by how they look when they’re trying to answer your questions. And that’s about film because film sees so much, just [in] the act of being so close up. I often like to talk about stuff that’s completely unrelated [to the film], if I can, just because you get a sense of who they are. Where they’re from is always intriguing to me. I love hearing people’s stories.

Was there any role in “Tramps,” you’re particularly proud to have figured out?

Michal Vondel, [who plays] Darren, [Danny’s] brother — and his real mother is his mother in the movie, so that was very funny. She is not an actress, but she is quite good in it and absolutely stunning in real life. And in all honesty, because I think the actor would tell people this, once we knew Callum was the guy, Michal came in for his audition and he was terrible. We put out a call for people who spoke Polish and I don’t know how many people we saw, but quite a lot and he was the guy who could be Callum’s brother, and once you realize that, you have to try to make that work. But [when] I saw [Michal’s] audition, I asked why he was in the room. We spoke a little bit about auditioning is and what an actor does to get a job. I wasn’t mean. I was clear. And I had to explain to him the reason why we were having this conversation is because you could be Callum Turner’s brother and you speak fluent Polish, and it is in your own best interests to do the best work you can do. So I gave him a week and he came back and he was the guy you see on screen. He’s really great, given how far he went, and now he has an agent and a manager. I didn’t know he was going to come back in a week later and be as good as he turned out to be, but I really do think he’s good in that movie.

Many of my favorite actors will appear in films you’ve cast again and again. Is there a stable of actors that you keep in mind that you know you can lean on?

Well, they all pop up. Once somebody does a really good job in something, how could you not think about them all the time? Callum is one of them. Grace is one of them. They go on every list you make moving forward. Louis Cancelmi, who plays the toughest guy in “Tramps,” the scariest one – he’s a wonderful New York actor and he usually plays these darker roles, but [I saw him in the comedy] “Gayby.” [For the criminals, Mike Birbiglia] and Adam, I believe, know each other, so once we thought that was going to happen, it set the rest in motion, which is that they’re criminals but not very good at it. They’re a little like, “Who are these guys?” but they’re acting tough, [which is] probably is how a lot of it really is, just some guys just trying to make some cash. And [Louis] is just so hilarious in “Gayby” that once you see that performance, he goes on every list you make. So these are just the people in the back of your head. [Of course] you can’t have them all in every movie you do.

Are there things that get you excited about movies you want to work on these days?

There’s a slight shift going on. I really always want to work on movies with people who I like. It’s hard enough to make a good movie and being surrounded by people that you care about and who care about you is really important. Obviously, the stories being told are always important to me and if it’s a filmmaker who’s made more than one movie [and I’ve admired their work], that’s important. I wish I could say it was a paycheck. [laughs]

What was it like seeing “Tramps”?

It’s super-colorful, vibrant, a little crazy and it has no cynicism and I have to tell you that is an amazing thing to be – that the thing [Adam] wanted to make is right on the screen. So it makes me feel great because how could it not? It’s just full of life.

“Tramps” starts streaming on Netflix on April 21st.