Deblo.ai
AI tutoring for 250 million African students
Educational platform for CP to Terminale with Pro tier for chartered accountants, lawyers, and auditors navigating SYSCOHADA. French-first. Phone + WhatsApp OTP authentication.
Building Deblo
The Day Déblo Refused a Correct Answer — Twice
A production trace showed Déblo K12 rejecting a Terminale student’s correct answer twice in a row. Eight hours of forensic work, four commits, one A/B-tested model rotation, and a 6-model benchmark later, the math tutor was fixed. Here is exactly what broke, what we changed, and what GPT-5.4-mini’s surprising failure on the Socratic test taught us about picking models for educational AI.
Web Claude Found the Bug. Then It Almost Made It Worse.
How a 270-line voice prompt for Deblo's Ultravox tutor was producing the same scripted greeting every call. Web Claude diagnosed it perfectly, then prescribed a fix that would have doubled the prompt size with non-existent backend hooks. The filter that kept the diagnosis and rejected the prescription.
Why I Had to Correct Web Claude Twice on Deblo's Home Page Strategy
How a 48-hour conversation with Web Claude almost led Deblo into the "ChatGPT for Africa" generalist trap, and why founder market knowledge had to override AI strategic suggestions twice. Plus: what serious AI-augmented product teams actually look like.
RAG Pipeline: Document Search With pgvector and Semantic Chunking
PostgreSQL with pgvector for embeddings, Datalab API for semantic chunking, Mistral Reranker for top-k refinement, and context compression at 150K tokens.
AI Memory and Context Compression
Fire-and-forget conversation summarization, the save_memory tool, and context compression at 150K tokens. How the AI remembers across sessions for $0.00005 per summary.
Building a React Native K12 App in 7 Days
20 sessions in 7 days: Expo SDK 54 monorepo, Zustand stores, SSE streaming, voice calls via LiveKit, biometric auth, and a custom tab bar.
The Agentic Loop: 24 AI Tools in a Single Chat
Up to 10 iterations of LLM calls, 24 tools from file generation to code execution, background jobs for 30-minute tasks. The agentic heart of Deblo.ai.
System Prompts That Teach: Anti-Cheating, Socratic Method, and Grade-Level Adaptation
Six-layer prompt assembly: root identity, school hours detection, grade overlays from CP to Terminale, subject expertise, and exam mode. How we taught the AI to teach.
WhatsApp OTP and the African Authentication Problem
Email does not work. SMS is expensive. WhatsApp is universal. How we built authentication for Africa with WhatsApp OTP, Google OAuth, and student access codes.
Credits, FCFA, and 6 African Payment Gateways
USD-cent pricing, 13 currencies, Orange Money and M-Pesa, 3 payment gateways, webhook-driven confirmation, and a background poller. Monetizing an African SaaS.
SSE Streaming: Real-Time AI Responses in SvelteKit
20+ event types, inline quizzes, file downloads, credit deductions, and tool progress -- all streamed in real-time via Server-Sent Events.
AI Tutoring for 250 Million African Students
The vision behind Deblo.ai: an AI tutor that speaks French, understands the African curriculum from CP to Terminale, costs pennies per question, and works on any phone.