Building a FastAPI + Vue 3 research platform: the 4 bugs that almost broke Phase 1

Oscar Rieken Posted on Jun 1 Building a FastAPI + Vue 3 research platform: the 4 bugs that almost broke Phase 1 # numpath # fastapi # docker # python Building NumPath (12 Part Series) 1 Why I'm building an AI math tutor for dyscalculia — and grounding it in 30 years of ITS research 2 Closing the feedback loop: how mistake classification drives adaptive problem selection in NumPath ... 8 more parts... 3 Why teachers need explainable AI, not just accurate AI — building the KC dashboard 4 Attempt history in the teacher dashboard — the scalar subquery pattern 5 Prompt engineering for teacher insights with Claude — structured JSON and graceful fallbacks 6 Bayesian Knowledge Tracing in 37 lines of Python — how NumPath models what a student knows 7 Building a FastAPI + Vue 3 research platform: the 4 bugs that almost broke Phase 1 8 Building a mistake taxonomy for dyscalculia — 8 error patterns, rule-based, no ML required 9 From Bayesian to deep knowledge tracing — upgrading NumPath's student model with a PyTorch LSTM 10 Clean Architecture in a FastAPI + Vue 3 monorepo 11 60 hand-crafted math problems: what I learned writing seed data for an adaptive tutor 12 Making LLM outputs auditable: the provider abstraction pattern Phase 1 of NumPath is done. Seven of eight Definition of Done items are checked — the eighth requires real children completing pilot sessions, which no amount of code will substitute for. The stack runs cleanly in Docker Compose, 56 unit tests pass, and a student can log in, answer ten problems, and see their knowledge state update in real time. What the commit history doesn't show is the afternoon I spent fighting four bugs that don't appear in any FastAPI or Vue tutorial. This post is that afternoon. What We Built NumPath is an adaptive math tutor for children with dyscalculia. Phase 1 ships the minimum research instrument: a student practice loop, a rule-based adaptive engine, and a read-only teacher dashboard. No ML yet — just clean infrastructu