The foundations every developer still needs.
AI writes the surface. Learn what is underneath, plus the new skills to direct, review and trust what AI builds.
Core
Core fundamentals
What every developer needs, and why it matters more now.
- 01How Computers WorkCPU, memory, processes and the call stack: what happens when your code runs.beginner
- 02Binary & Number SystemsBinary, hexadecimal and bitwise operations: how a computer stores every value.beginner
- 03Command LineNavigate, run and automate your environment from the terminal.beginner
- 04Version ControlGit commits, branches, merges and conflicts: how teams change code safely.beginner
- 05Networking BasicsHTTP, DNS and TCP/IP: the request/response cycle your apps live in.beginner
- 06APIs & ProtocolsREST, WebSockets, GraphQL and gRPC: how systems talk to each other.beginner
- 07Package Managementnpm, pip and cargo: dependencies, versions and lockfiles.beginner
- 08Programming ParadigmsProcedural, object-oriented and functional styles, and when each one fits.medium
- 09Big O ComplexityHow time and memory grow with input size, and how to spot the slow path.medium
- 10Data StructuresArrays, hash maps, stacks, queues, trees and graphs.hard
- 11AlgorithmsSorting, searching, recursion and dynamic programming.hard
- 12DatabasesRelational vs document stores, queries, indexes and data modeling.medium
- 13TestingUnit, integration and end-to-end tests, and what each one proves.medium
- 14Security BasicsAuthentication, encryption and the vulnerabilities that ship most often.medium
- 15Design PatternsNamed, proven solutions to problems that keep coming back.medium
- 16Operating SystemsProcesses, scheduling, file systems and permissions.hard
- 17Concurrency & AsyncThreads, the event loop, promises and async/await.hard
- 18Compilers & InterpretersLexing, parsing and ASTs: how source code becomes something that runs.hard
- 19Statistics & ProbabilityDistributions, variance, Bayes and hypothesis testing.hard
- 20Linear AlgebraVectors, matrices, dot products and transformations.hard
- 21Calculus for MLDerivatives, gradients and the chain rule behind backpropagation.hard
Engineering
Beyond the code
System design, architecture and the habits that keep real software running.
- 22Code ReviewGive and take review: spot risk, ask the right questions, keep changes small.beginner
- 23Technical Writing & DecisionsREADMEs, design docs and decision records that explain why, not just what.beginner
- 24Clean Code & RefactoringNaming, small functions, removing duplication and changing code safely.medium
- 25API DesignResources, versioning, pagination, errors and idempotency.medium
- 26Containers & CI/CDDocker, build pipelines and automated deploys that make shipping boring.medium
- 27Observability & Production DebuggingLogs, metrics and traces: find out what a live system is doing.medium
- 28Reliability & Failure HandlingTimeouts, retries, backoff, rate limits and graceful degradation.hard
- 29System DesignServices, data stores and queues, reasoned about under load and failure.hard
- 30Software ArchitectureLayers, boundaries, monolith vs services: keeping a codebase changeable.hard
- 31Scalability & CachingHorizontal scaling, load balancing, caches and finding the real bottleneck.hard
- 32Queues & Event-Driven DesignBackground jobs, message queues and events that absorb spikes.hard
AI era
Skills for the AI era
Work that exists because AI now writes code.
- 33Prompting & ContextGoals, constraints, examples and the right context in the window.beginner
- 34Reviewing AI-Written CodeRead generated code like a pull request from a confident junior.medium
- 35Debugging Code You Didn't WriteForm a hypothesis, narrow it down, fix the cause instead of re-prompting.medium
- 36LLM APIs & Tool UseMessages, streaming, structured output, function calling, cost and failures.medium
- 37Evals & Hallucination ChecksTest sets and graders that measure whether an AI feature works.hard
- 38AI SecurityPrompt injection, over-permissioned agents and untrusted model output.hard
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