Casting director Jennifer Venditti had one of Hollywood’s great chameleons to work with when she was putting together the pieces for HBO’s limited series The Sympathizer. Robert Downey Jr. plays a quartet of characters in Park Chan-wook and Don McKellar’s adaptation of Viet Thanh Nguyen’s 2015 Pulitzer Prize-winning novel as the Oscar-winning performer is in a constant swirl of dramatic action among performers less well-known but all of them entirely game.

The show follows the twisting journey of Captain (Hoa Xuande), a communist operative working as a mole in South Vietnam’s army who ends up escaping to the U.S. alongside his nominal boss, the General (Toan Le). The Captain ends up in California, where he remains embedded in a South Vietnamese refugee community where he monitors and reports to the Viet Cong. It’s a fitting city for the Captain to make a new home—a town built on illusion; the Captain interacts with a bevy of Americans in various positions to aid and potentially abet his machinations. One of those is a CIA operative named Claude (Downey), whom the Captain met in Vietnam; while in the U.S., the Captain comes into contact with ingratiating California congressman Ned Godwin (Downey) and the filmmaker (Downey again), a bearded 1970s auteur.

Hoa Xuande and Roberty Downey Jr. Photograph by Hopper Stone/HBO

Surrounding Xuande, Le, and multiple Downeys is a rotating cast of scene-stealing performers, each perfectly calibrated to the series’ twisty, darkly comedic tone. Venditti, a seasoned casting director who has populated some of the most memorably offbeat casts in recent memory, including two standout films in 2019, the Safdie Brothers’ Uncut Gems and director Alma Har’el’s Honey Boy, put her years of experience to work when she populated one of the year’s most satisfyingly diverse and delicious series. Venditti takes us through her intuitive process.

When you take on something like The Sympathizer, which comes from award-winning source material, are you taking any cues from Viet Thanh Nguyen’s novel?

Good question. When A24 first contacted me, I had not read the book, but my casting associate, Alan Scott Neal, said it was his favorite book. So he was the person that really was like, “Oh my God, we have to do this. This is amazing.” And so I read the script. I was obviously a huge fan of director Park and had worked for HBO and A24 before, so it seemed like a no-brainer. But the first way in was the script for me, and then I read the book. Then, there were really detailed conversations with director Park and co-showrunner Don McKellar about their visions because they both had very clear ideas of how they envisioned these characters coming to life. Then it’s the process because you can have these ideas of what you’re looking for, and then the process shows you and materializes things in a way you might not have seen.

What materialized for you during the casting process?

Like with Bon [Fred Nguyen Khan], director Park really wanted someone with a physicality to them. Fred had done stunts and martial arts, so you talk about it, and as you look and search and people show up, you start to put it all together. That’s my favorite part of the process: learning about it and then letting it go and allowing the mystery of the search to bring things together. Fred and Hoa had such good chemistry; things like that are very cool when they happen.

oa Xuande, Fred Nguyen Khan. Photograph by Hopper Stone/HBO

So, in a sense, the project reveals what it wants to be.

And it’s interesting, I’m really not that kind of person. One of the things I do like is discoveries, and one of the reasons they might have reached out to me for this is because they knew I was going to have find a lot of people, we weren’t going to find everyone from traditional casting because of the requirements of the script. So there’s some part of me that really likes the mystery and discovery rather than just going with people I already know.

Phanxinê, Fred Nguyen Khan, Toan Le. Photograph by Hopper Stone/HBO

HBO and A24 both have really solid track records for casting really interesting ensembles, whether it’s Mare of Eastown

HBO cares so much about casting; it’s so important to them. So they’re very much involved in the process, and A24 is great like that two, they both have really good taste an they’re great at supporting the process and letting you do what you do best, but they also have great notes. You look forward to their notes because you’re seeing so many people. It’s great to get feedback from people you respect who really take it seriously and have such a good eye as well.

Obviously, for American audiences, you’ve got one of the biggest stars in the business in Robert Downey Jr., not only in the series but in multiple roles. Then you’ve got Sandra Oh, another amazing performer, and then you’ve got all these folks who are lesser known but who more than hold their own. What’s it like mixing these two worlds of performers?

I have a chapter in my book [“Can I Ask You A Question?”] about this called “The Alchemy of Casting,” I do think there’s something beautiful about what happens when you take someone who’s so grounded and clear and experienced in knowing where a scene is going to go and then you take someone with less experience, there’s wild alchemy about that where there’s something about the person who’s not as experienced make it more alive for the more experienced performer, and then the experienced person grounds the other person. And as intimidating as you might think it is for a newcomer to be across from Robert Downey Jr., across the board, what everyone has said is working with him, he’s so generous, he makes you so comfortable, he’s so intuitive, he can feel when you’re not feeling good about it, and he can help drop into that with you and put you at ease.

Is there a specific pairing you’re thinking of?

For example, Toan Le, who plays the General, his story is amazing. He has all these scenes with Robert Downey Jr. and he kills it. People say you’re only as good as your scene partner, and I think Robert being that good lends to the other person. Toan was someone who had wanted to act since he was young, and in his 20s, he’d been in plays, but there just weren’t roles for Vietnamese actors. So he got a day job as a graphic designer for years, and he saw our open call and sent in a tape, and then became a series regular. People always think that only happens for young people and that people aren’t taking risks like that later in life, and he went for it. He’s a great example of someone who really held their own, and Robert really leaned in and supported them.

This type of live wire alchemy is really present in many of the movies you’ve cast, especially in the Safdie brothers’ Uncut Gems and Good Time.

It’s magic. When I was young, I didn’t really watch movies or TV; I was obsessed with people-watching, and the Safdies were the same way. A lot of the people that I work with enjoy that, too. For this project, if we could have just found everyone by reaching out to an agency, then we would have done it, but for this project, we had to search high and low because of all the diversity that wasn’t easily available at our fingertips. It was definitely intimidating, but there’s something about aliveness that lends to the magic on the screen. Sandra, too, and everyone said the same about her. We were lucky to have these gracious actors who created a safe space for the newer performers.

Alan Trong, Sandra Oh. Photograph by Hopper Stone/HBO

The Sympathizer is also about performance in a way…

Yeah, it’s meta because the idea is everyone’s an actor in their real lives. Do you know what I mean? This meta thing, I’m casting people to be human to portray a character, but we’re all doing that in our real lives as well.

How long do you feel like it took for you to feel comfortable just knowing during an audition, okay, this is working, or these two people have the right chemistry?

I think sometimes chemistry readings are necessary, but then, Robert Downey Jr. could have chemistry with a dead person [laughs]. Let’s not get it twisted. I’m not really worried about him having chemistry with anyone. There are certain things, like Hoa as the Captain and Fred as Bon, that was kismet in a way. We cast Fred first, and we had no idea that they knew each other and they’re best friends in real life. The beauty of this project is that the cast is so in love with each other. They all have such deep friendships, it happened on set, and it’s continued since then. It’s really cool when it translates past the project. There are a lot of things that are intuitive, and sometimes there are processes where you’re really trying to make it work, and this was one where it was really natural, and everyone seemed to have a really meaningful connection with each other. This was a shared experience to be a part of something so personal and to come together and connect on a deeper level.