Erica Du

Erica Du (杜帆) is the co-founder and CTO of Toko, an AI language-learning service she founded with CEO Jen Liu. Her work includes jointly building its early prototype, seeking applicants for its first engineering hire, and demonstrating an interface that combines learner-directed conversation with grammar feedback.[2][3][4][5][1]

Du recalled in an April 2022 post that she and Jennifer Liu had built the first version about a year and a half earlier: a “small, weekend project intended to help us grow closer to our grandmas.” Liu later described that prototype as GPT 奶奶, an AI Grandma built with GPT-3 to practice Mandarin. According to Liu, the pair shifted toward an English tutor for learners in East Asia after recognizing greater demand for English learning.[5][8]

Toko was founded in 2021 and joined Y Combinator’s Winter 2022 batch. In April 2022, Du was recruiting Toko’s first engineer after working with a small team of contractors. She reported that the service then had more than 500 subscribers and over 150 dynamic, voice-based conversation topics.[3][5]

Du demonstrated Toko at the NYC AI×UX meetup described in Paul Butler’s June 2023 recap in Latent Space. The interface let native Chinese speakers steer a freeform English conversation with an AI while receiving grammar suggestions. It provided conversation practice for learners who lacked regular opportunities to speak English, pairing an open-ended exchange with feedback of the kind a teacher would give.[1]

In November 2025, Liu announced Toko for Mandarin, returning to the language of the original prototype. She said she and Du had used an internal version for roughly a year to prepare for user interviews and communicate better with family. Liu credited Kenny Wong with driving the release, alongside the team.[8]

Before Toko, Du worked in engineering at Palantir, Codecademy and Google and earned BS and MEng degrees at MIT. Her earlier research at Cornell Tech’s Digital Life Initiative focused on algorithmic accountability and fairness; Cornell lists her among its former research fellows.[2][3][6][7]

In her 2019 essay, Du traced her turn toward ethics to discussions at Palantir in May 2018, where she felt she lacked the vocabulary to articulate her own ethical views. At Cornell, she exchanged engineering questions such as “Will this scale?” for “What does fairness mean?” Her fairness research raised further questions rather than producing the concrete deliverables she had been accustomed to; during the second half of her fellowship, she built small civic software projects through community engagement and user interviews.[6]

Du argued in that essay that a socially minded technologist should accept that “technology is political” and make intentional choices about embedded values, whom a system empowers, and how product design and business models protect users. As her Cornell period ended in May 2019, she identified a Blue Ridge Labs fellowship as her next step; her personal site lists it among her past roles.[6][2]