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Long-running workflows, retries, timeouts, and schedules

AI Engineering·Workflow orchestration

Long-running workflows persist progress while waiting for jobs, timers, or people. Retries repeat transiently failing work; timeouts cap waits; schedules start work at defined times. Durable waiting should not consume an open request or a sleeping application…

Intermediate2 min read

Idempotency, compensation, and human approvals

AI Engineering·Workflow orchestration

Idempotency makes repeating the same logical request avoid repeated effects. Compensation is a business action that offsets an earlier action when later steps fail. Human approvals are authenticated events permitting specific transitions.

Intermediate2 min read

Choosing orchestration tools

AI Engineering·Workflow orchestration

Workflow engines and job systems provide different guarantees for dispatch, persistence, recovery, waiting, and coordination. Temporal is a durable workflow platform; BullMQ is a Redis-backed job library; Inngest and Trigger.dev offer developer-oriented…

Intermediate3 min read

MCP architecture: host, client, and server

AI Engineering·Model Context Protocol (MCP)

MCP is a protocol for connecting AI applications to external tools and context. The host is the application using the model; a client is its protocol connection to a server; a server exposes supported capabilities. The model normally proposes operations,…

Intermediate2 min read

MCP tools and tool discovery

AI Engineering·Model Context Protocol (MCP)

A tool is a named executable capability with argument metadata and a schema. Discovery lets a client obtain the server's available tool descriptions. A tool description helps the model choose a capability; it is not proof that the server or tool is…

Intermediate2 min read

MCP resources and prompts

AI Engineering·Model Context Protocol (MCP)

Resources expose readable context through identified locations, such as policy documents. Prompts expose reusable task templates and arguments. Tools perform operations; resources provide content; prompts help compose a task.

Intermediate2 min read

Authentication, authorization, and permissions

AI Engineering·Model Context Protocol (MCP)

Authentication establishes who a client/user is; authorization determines what that identity may do. MCP connection authorization and downstream business authorization are separate concerns. A valid connection does not automatically permit every customer's…

Intermediate2 min read

MCP versus REST, function calling, and plugins

AI Engineering·Model Context Protocol (MCP)

REST is an HTTP API design style for application services. Function calling is a model interaction mechanism for proposing structured operations. MCP standardizes integration discovery and invocation/context exchange; a plugin is a packaging/integration…

Intermediate2 min read

Conceptual MCP server: four business tools

AI Engineering·Model Context Protocol (MCP)

This example defines server-side contracts and dispatch logic, not a particular MCP SDK's registration syntax. Attach this registry to the selected SDK's authenticated request handlers, implement capability discovery, and encode its documented result…

Intermediate2 min read

Context, short-term memory, and conversation memory

AI Engineering·AI memory

Context is what the model sees now. Short-term memory is task/session information retained across nearby steps. Conversation memory is selected dialogue history or a summary used to maintain continuity.

Intermediate2 min read

Long-term, semantic, episodic, and user-profile memory

AI Engineering·AI memory

Long-term memory stores selected information beyond one task. Semantic memory contains facts or preferences; episodic memory records past events; user-profile memory contains explicit attributes such as preferred language. These categories overlap and should…

Intermediate2 min read

State persistence and checkpoints

AI Engineering·AI memory

State persistence stores task progress; checkpoints record recovery positions. Neither automatically means user preference memory. A durable claim workflow may need execution records even when conversational history is deleted under a different retention…

Intermediate2 min read

Context summarization and memory retrieval

AI Engineering·AI memory

Summarization compresses earlier interaction into a shorter record. Memory retrieval selects relevant stored entries, sometimes through vectors and metadata. Both reduce context volume but can lose or distort information.

Intermediate2 min read

Prompt injection, indirect injection, and jailbreaking

AI Engineering·AI security

Prompt injection is an attempt to make a model follow an attacker's instructions instead of the intended task. Indirect injection places those instructions in external content, such as a PDF, webpage, email, or tool result. Jailbreaking generally attempts to…

Intermediate2 min read

Tool poisoning and excessive agency

AI Engineering·AI security

Tool poisoning uses malicious tool definitions or descriptions to influence model behavior. Excessive agency gives the AI more permissions or autonomy than its task needs. A harmless-looking tool name can conceal a sensitive operation or destination.

Intermediate2 min read

Data leakage, PII, sensitive data, and secrets

AI Engineering·AI security

Data leakage is unauthorized disclosure. PII means personally identifiable information, such as identity-linked names, contact details, and account identifiers. Sensitive business or health information and credentials need protection even when they do not fit…

Intermediate2 min read

Authentication, authorization, least privilege, and tenant isolation

AI Engineering·AI security

Authentication verifies identity. Authorization decides allowed objects and actions. Least privilege grants only required capabilities; tenant isolation keeps one organization's data and operations separated from others.

Intermediate2 min read

Validation, rate limiting, and secure database access

AI Engineering·AI security

Input validation checks permitted shapes and values; output validation checks generated data before use. Rate limiting constrains requests or resources by user, tenant, and operation. Secure tool services mediate database/API access through known business…

Intermediate2 min read

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