Introductory
Linear Algebra with Python
Linear systems and matrices, and the vector space structure underlying them, implemented in NumPy.
20 lessons2 modules
Software EngineerSoftware Engineer · AI · M.Sc. in MathematicsI'm Alejandro
I'm Alejandro
Sánchez Yalí
I build LLM systems that hold up in production: agents, RAG and evals. Open to remote software and AI engineering roles and contract work.
Selected work
Case studies of systems I designed and built: the architecture, the decisions and what came out of them.
case-studyaluna
Building Aluna: six agents, structured output, and a receipt that outlives the data
The third engineering case study: how Aluna screens candidates with six specialised agents instead of one chatbot, why e…
case-studycrearia
Building CREARIA Agent: RAG, MCP tools, and a queue that changed the design
The second engineering case study: how CREARIA Agent answers customer questions on WhatsApp using RAG over pgvector and …
case-studyplixiq
Building Plixiq: a multi-tenant WhatsApp AI agent platform
A behind-the-scenes case study of Plixiq — why we picked FastAPI, Next.js, LiteLLM and a modular monolith to run AI agen…
Courses
Free courses where I teach the math and engineering behind modern AI, from the original formulations.
Intermediate
Foundations of LLMs
What exactly is optimised when a language model is trained: self-supervised pre-training, the scaling laws and their correction, and the objectives that separate one architecture family from another.
8 lessons2 modules
What I build with
Python and TypeScript on the backend and frontend, PostgreSQL and Redis for data, and LLM providers behind one interface.
Study Community
Join a weekly study group to explore mathematics, software engineering, and artificial intelligence together.
∑Mathematics
⚙Software Engineering
🤖Artificial Intelligence