EF
Beta

Engineering Fluency OS

From zero to system-level architectural fluency. Master the smallest set of concepts that unlock the largest mental leverage — one idea at a time.

Start your journey

Begin with variables — the foundation of everything.

Progress

Domains

Each domain is a self-contained curriculum. Complete them in order, or jump to what you need.

Programming Foundations
13 lessons

Core concepts every programmer needs — variables, control flow, and functions.

Data Structures & Algorithms
14 lessons

The building blocks of efficient computation — arrays, trees, graphs, sorting, and searching.

Git & Version Control
5 lessons

Track changes, collaborate on code, and ship with confidence using Git and GitHub.

Operating Systems
10 lessons

How computers manage processes, memory, and I/O under the hood.

Computer Hardware
4 lessons

From bare metal to boot — CPUs, memory, storage, and how hardware becomes software.

Networking
9 lessons

How computers communicate — protocols, DNS, HTTP, TLS, and load balancing.

Databases
9 lessons

Storing, querying, and managing data — relational models, indexes, transactions, and replication.

System Design
8 lessons

Architecting scalable systems — client-server, microservices, caching, and observability.

Distributed Systems
10 lessons

Building reliable systems across multiple machines — consensus, replication, and fault tolerance.

Production Engineering
6 lessons

Shipping and operating software — CI/CD, containers, observability, and incident response.

Mathematics for CS
7 lessons

The math behind computing — linear algebra, probability, optimization, and calculus essentials.

Machine Learning
8 lessons

Teaching computers to learn from data — supervised learning, loss functions, and model evaluation.

Deep Learning & LLMs
8 lessons

Neural networks, transformers, and large language models — from perceptrons to prompt engineering.

Arithmetic
8 lessons

Number sense, operations, fractions, and the foundation all mathematics builds on.

Algebra I
10 lessons

Variables, equations, and learning to think abstractly about quantities.

Geometry
8 lessons

Shapes, space, measurement, and the first encounter with formal reasoning.

Logic & Proofs
8 lessons

Propositions, logical connectives, truth tables, and proof techniques.

Algebra II & Precalculus
8 lessons

Advanced functions, exponentials, logarithms, and preparing for calculus.

Trigonometry
6 lessons

Angles, triangles, unit circle, and periodic functions.

Calculus I
15 lessons

Limits, derivatives, integrals, and the Fundamental Theorem of Calculus.

Calculus II
8 lessons

Integration techniques, sequences, series, and Taylor expansions.

Linear Algebra
8 lessons

Vectors, matrices, transformations, eigenvalues — the math behind ML and graphics.

Multivariable Calculus
8 lessons

Partial derivatives, multiple integrals, vector fields — calculus in higher dimensions.

Probability & Statistics
10 lessons

Counting, distributions, hypothesis testing, and Bayesian reasoning.

Differential Equations
6 lessons

Modeling change over time — ODEs, systems, and the Laplace transform.

Discrete Mathematics
6 lessons

Counting, graphs, recurrences, and number theory — the math of CS.

Real Analysis
6 lessons

Rigorous foundations — epsilon-delta, convergence, and the structure of the real numbers.

Abstract Algebra
4 lessons

Groups, rings, fields — the deep structure beneath arithmetic and beyond.