Thirty years on from its dissolution, the legacy of apartheid still weighs heavily on South African cinema, as a new, outspoken generation of Black filmmakers grapples with truths and wounds that they previously had limited scope to voice. But rage over the past fuses remarkably with assertive, forward-looking investment in the future in “Milisuthando,” a self-titled and duly self-searching documentary from artist turned filmmaker Milisuthando Bongela. With spiky candor and a flourish of personal poetry, Bongela’s debut feature probes her experience as a millennial Black woman who only began reckoning with apartheid as her country was stumbling out of it.

Despite a slightly slack two-hour-plus runtime, this inventive standout from Sundance’s world cinema documentary competition should easily find a home in future docfest programs, and with specialist distributors and streaming platforms.

As she explains in her running, mellifluous narration, Bongela is a child of a country that no longer exists. She was born in 1985 in Transkei, a nominally independent homeland for the Xhosa people that South Africa had designated nine years before — though it remained, for its 18-year existence, an internationally unrecognized state. Its autonomy was an illusion, granted entirely on the terms of apartheid, in the interests of separate racial development. Yet to the young Bongela, growing up in a wholly Black community without visible white intervention, that freedom seemed real — shattered only when, as apartheid ended, Transkei was reintegrated and Bongela’s family moved to a mixed South African city, she gradually realized her identity had been formed “inside apartheid’s wish.”

It’s a revelation that Bongela, now an artist and writer based in Johannesburg, is still processing, as she ponders a lingering sense of disorientation from having had an all-consuming culture of racism systemically hidden from her. “Was it because I was in a segregated place that I felt rooted in the closest thing to belonging that I’ve ever known?” she asks.

To her nonagenarian grandmother, still living on the rural family homestead in the former Transkei, the end of apartheid also marked, in a sense, the end of her identity: Chattering away to Bongela in a faded bathrobe, she sharply blames South Africa’s first post-apartheid president, Nelson Mandela, for “killing the Xhosa culture” with “racial mixing.” Upon hearing that Bongela’s brother is dating an Asian woman, she admonishes him on the same charge: Even in some of its victims, the psychology of racial segregation dies hard.

“Milisuthando” uses a minimum of dates and facts to paint its vivid portrait of a country in the grip of white Afrikaner ideals: Instead, the film presents an extraordinary 12-minute archival montage that crosscuts between the everyday rituals and ceremonial traditions of Black and white communities in the apartheid era, from Bantustan poverty to Volkstaat privilege, to a soundtrack that blends indigenous music, Wagner’s “Das Rheingold” and Jeremy Taylor’s satirical protest song “Piece of Ground,” sung by Bongela herself. (“When the white man first came here from over the sea, he looked and he said this is God’s own country,” it begins. The final verse is not voiced, though older South African viewers might fill it in for themselves: “I’ve heard a rumour that’s running around that the black man’s demanding his own piece of ground.”)

Brilliantly edited by Hankyeon Lee (who, as DP, also contributes some of the film’s most striking imagery of bleached skies and parched landscapes) to a swirling, immersive rhythm that audaciously connotes the sell of political propaganda, this formal centerpiece cues a less lyrical, more plainspoken reflection on the growing pains of post-apartheid South Africa. In 1992, with the transition to democracy under way, Bongela’s family moved to the Eastern Cape, and her uneasy social integration began.

“We started using words like cul-de-sac and hedge,” she says drolly; more significantly, like many Black children in the early ’90s, she began attending a formerly all-white school, ostensibly welcomed but still othered by her former oppressors. (She responded by silently othering them, noting “their hair as soft as their names.”) Today, having come of age with permissions and privileges once denied her elders, Bongela feels a liminal sense of slivered identity, belonging neither quite to the former Transkei motherland that still pulls her with memories of childhood stability and contentment, nor to the diverse metropolis that she shares with friends both Black and white.

To the latter, who include her producer Marion Isaacs, she’s coolly candid, initiating thoughtful conversations — mostly over a black screen, all the better to consider different styles of speech and address, and the possible social baggage of that difference — on their unconscious microaggressions toward her and her instinctive responses to them. (She gets a chill, she admits, when a white friend benignly asks her to turn the music down.) “Do you remember the first time you realized you were white?” she asks one toward the film’s end — a question that, by this late point in Bongela’s sharp, searching investigation of South African Blackness, whiteness and gray areas, is nowhere near as simple as it sounds.