Small ideas.
Useful understanding.

learn / aws-lambda

AWS Lambda can invoke configured function code in response to a request or event; permission to invoke it is separate from the execution-...

learn / back-pressure

Back-pressure lets downstream capacity influence how much new work an upstream producer sends or the receiver accepts; a signal must be h...

learn / bin-packing

Bin packing places every whole item in a fixed-capacity bin while seeking the fewest bins; a legal placement need not be an optimal one.

learn / capacity-and-placement

A capacity limit states how much a container can hold; a placement assigns whole items to containers while keeping each total within that...

learn / client-server

In a client/server interaction, the client initiates a request and the server responds; these are roles in that interaction, not permanen...

learn / cloudformation-nested-stacks

A nested stack is represented by a stack resource in a parent, so a separately defined template can be composed into a managed hierarchy.

learn / configuration-values

A named configuration value supplies a setting an application can read and use; a saved change and the setting currently in use can differ.

learn / connection-pool

A connection pool manages a limited collection of database connections for checkout and reuse; when no usable connection or spare capacit...

learn / connections-and-reuse

An application can borrow a database connection, use it and return it for another request; a limited number of reusable connections means...

learn / cqrs

Separate the models used to change information from those used to present it, when the benefits justify the added complexity.

learn / event-sourcing

Keep the accepted event stream as the authoritative record and reconstruct the modeled state by applying it in order.

learn / file-paths

A path tells a tool where to look; a relative path needs a starting location.

learn / files-and-folders

Files hold content; folders organize files and other folders so you can find your work.

learn / functions

A function is a callable unit of behavior: its definition describes the rule, while an invocation supplies arguments and runs that rule t...

learn / http-request

An HTTP request is a client's message asking a server to handle a method and target, with headers and sometimes a body; the request alone...

learn / http-response

An HTTP response answers a particular request with a status, headers and sometimes a body; its meaning can be an acknowledgement rather t...

learn / iam-role

An AWS identity that authorized people or services can assume to use a temporary session with specified permissions.

learn / idempotency

Repeating the same operation has the same intended effect as applying it once; that does not guarantee identical responses or harmlessness.

learn / identity-and-credentials

An identity names the caller a system is treating as an actor; a credential supplies evidence for an access mechanism, while permission i...

learn / infrastructure-stacks

A CloudFormation stack groups managed cloud resources; a template describes the plan, while an operation’s observed result tells you what...

learn / lambda-cold-start

A Lambda cold-start path includes work to prepare an execution environment before its handler runs; a warm invocation can reuse a prepare...

learn / latency-and-distributions

Latency is elapsed time between stated points. Keep the individual durations: an average and a percentile describe different parts of tha...

learn / oauth-scope

Provider-defined access labels that an OAuth client can request; the authorization server decides the actual grant.

learn / permissions-and-access

Permissions describe which actor may perform a particular action on a particular resource; being allowed is different from the action suc...

learn / producers-consumers-and-queues

A producer offers work, a consumer takes work to process, and a queue holds waiting items; acceptance, being in service and completion ar...

learn / reading-and-saving-data

Reading asks what information is stored; saving asks an application to change what it keeps.

learn / retry-with-backoff

Delaying eligible retries, with limits and jitter, can reduce pressure on a struggling dependency; waiting does not guarantee recovery or...

learn / run-program

Running a program asks a language tool or executable to perform its instructions; it is separate from editing the file.

learn / shell-command

A shell command asks the shell to perform an action, often by running a tool with arguments.

learn / source-code

For a text-based language, source code contains the program’s instructions; a language tool gives them meaning.

learn / ssm-parameter-store

AWS Systems Manager Parameter Store holds named configuration values that applications retrieve under appropriate access; retrieving Secu...

learn / state-and-events

State describes what is true now; an event records a particular change that happened.

learn / tail-latency

Tail latency describes the higher-duration end of a stated observation distribution. A mean can hide slow responses; percentile methods, ...

learn / terminal

A terminal is a text interface to a shell and other programs, not a separate programming language.

learn / text-editor

A code editor lets you save plain-text source files; saving them is separate from running them.

learn / url

A URL identifies a resource's address; in a simple HTTPS URL, the host names the intended service and the path identifies a target within...

learn / webhook

An event notification sent as an HTTP request to an endpoint you configure, so your application can react without repeatedly polling.

learn / working-directory

The working directory is the location a shell uses when resolving ordinary relative file paths.