In progress
PhD Thesis — Intertextuality & Causality
A semantic analysis of discourse bridging NLP with SAT-based formal methods, from echoes between migration narratives to causal network discovery in biographical trajectories.
NLP for languages the industry forgot
Ngambay · spoken by ~1M people in Chad
Sakayo Toadoum Sari
PhD candidate in AI at CRIL-CNRS, Université d'Artois, working on discourse semantics and causal reasoning. Lead NLP Engineer at PlotWeaver, building voice AI for African languages. If your language isn't in the dataset, build the dataset.
01 · About
I grew up in Chad speaking a language with almost no digital footprint. Today I build the technology that gives languages like mine one. My research at CRIL-CNRS (UMR 8188) connects two worlds that rarely meet: discourse-level NLP and formal methods, probing how texts echo one another and how causal structure can be extracted from narratives, with formal guarantees rather than heuristics.
Outside the lab, I'm Lead NLP Engineer and a founding member of PlotWeaver, where I lead production ASR, TTS, and MT for African languages, and I teach algorithmics at Université d'Artois. On YouTube, Sakayo Tech brings AI education in French to students across francophone Africa, and my mentorship program supports a first cohort of 20 young innovators in Chad.
I've worked with UNICEF, EPFL, and Batazia, and I contribute to the Masakhane and AfricaNLP communities as a researcher and reviewer.
02 · Current work
A semantic analysis of discourse bridging NLP with SAT-based formal methods, from echoes between migration narratives to causal network discovery in biographical trajectories.
Detecting experiential intertextuality in migration narratives. Shows lexical methods beat semantic embeddings on this task, and explains why.
Solo end-to-end French RAG pipeline built under strict compute constraints, scoring above the field mean on all six official metrics.
ASR, TTS, and MT for African languages, starting with Yoruba, Igbo, and Hausa, deployed on AWS SageMaker for enterprise clients.
Probing with inclusion-minimality guarantees, interpretable rule models with formally minimal explanations, and parameter-efficient fine-tuning studies.
AI education series in French for African students: concepts, careers, and hands-on tools, published twice a week.
03 · Publications
04 · Journey
First papers accepted (SIGDIAL, CORIA-TALN). Teaching algorithmics. Lead NLP Engineer at PlotWeaver, voice AI in production.
Joined CRIL on the ANR HYCI project. RCCE consultancy for UNICEF in Chad. Built African ASR/TTS systems at CDIAL.
MSc in Machine Intelligence as a Google & Meta Scholar. Research internship at EPFL on polarization detection. NLP engineering at Batazia. Trained 40+ students in Python and ML.
MSc in Industrial Mathematics as a MasterCard Foundation Scholar.
BSc in Applied Physics, then MSc in Physics. First steps in web development and ML at Limbe City Council.
05 · Skills
06 · Contact
Building something for underserved languages, or want to collaborate on discourse, causality, or African NLP? I'd love to hear about it.