How LLMs Work: An Engineer’s-Eye ViewTokensThe Transformer and AttentionIn-weights knowledge versus in-context knowledgeThe context window is your working-memory budgetWhy LLMs Are Good at CodeTraining with verifiable outcomes: RLHF and RLVRChain-of-thought and reasoning modelsNondeterminism, Temperature, and SamplingThe Model LandscapeOpen source versus closed sourceSmall language modelsMultimodal modelsEmbeddings and semantic searchWhere LLMs Excel and Where They FailBenchmarks: What They Do and Don’t MeasureThe API Layer: How Engineers Talk to LLMsWhat Makes an Agent: LLM, Tools, Context, LoopThe LLM: The reasoning coreTools: How agents act on the worldContext: Accumulated stateThe agentic loop: Reason, act, observe, adjustBeyond single agentsBuilding an Agent in 50 Lines of CodeStopping conditions and iteration limitsAgent frameworksWhy this matters for users of coding agentsThe Agent Execution Model: Reason, Act, ObserveThe self-correction loop: Tests as observationsTool Use and Function CallingHow function calling works under the hoodMemory and StateIn-context memoryLong-term memory through filesRetrieved memory with RAGAgent-generated memoryContext rotAgent Economics: Cost, Latency, and ScopeHuman-in-the-LoopHITL as a design principleThe agent decides when it needs youCalibrating HITL to riskThe AI Tool LandscapeIDE-integrated coding assistantsCLI and terminal-native agentsCloud and background agentsCode review assistantsDesign and UI generation toolsChoosing tools without chasing hypeSummary