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Software: explore STEM content (page 13 of 25) · openstem

All fields Software Mathematics Physics Chemistry Biology Engineering Astronomy Environmental Other Software Software groups

Explore STEM Content

Search the community's STEM library — free to study, yours to make your own.

Software

Programming, algorithms and systems on openstem — flashcards, notes, quizzes, sketches and flowcharts shared by the community. Study free, or clone anything into your library.

Content Groups1

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Flowchart22 objects

Software

Software · L4 · Incident lifecycle

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Software · L4 · Incident lifecycle

Collection2 items

01Git Internals: Objects, Refs & Plumbing

02History Rewriting, Recovery & Advanced Workflows

Software

Software · L4 · Git & Dev Workflow

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Software · L4 · Git & Dev Workflow

Quiz5 questions

Why does containment happen before eradication in incident response?

AEradication is always faster, so it should come lastBIsolating the affected system stops ongoing damage while investigation continuesCContainment and eradication are the same stepDBecause backups must be restored first

Software

Software · L2 · Security & Auth: Incident Response Basics

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Software · L2 · Security & Auth: Incident Response Basics

Collection2 items

01Performance

02Server Components & Suspense

Software

Software · L3 · React

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Software · L3 · React

Quiz7 questions

Why does range-based sharding on a monotonically increasing key cause a hotspot?

ABecause range sharding requires more storage per shardBBecause all new writes land on whichever shard currently owns the highest rangeCBecause range sharding disables replicationDBecause it forces every read to scan all shards

Software

Software · L4 · Data Partitioning & Replication — 7 Q

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Software · L4 · Data Partitioning & Replication — 7 Q

Note~581 words · 3 min

Resources, Not Actions A REST API is organized around resources — nouns like orders, users, or invoices — addressed by URLs, with the HTTP method supplying the verb. A well-modeled API reads as a set of collections and items: /orders is a c

Software

Software · L3 · API Design & REST

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Software · L3 · API Design & REST

Flowchart14 objects

Software

Software · L2 · React: Effect Lifecycle · flowchart

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Software · L2 · React: Effect Lifecycle · flowchart

Note~439 words · 2 min

Concurrency patterns and pitfalls Concurrent programming allows multiple tasks to make progress simultaneously, but introduces hazards that single-threaded code never encounters. Core hazards Mutex (mutual exclusion lock) A mutex allows onl

Software

Software · L4 · Concurrency patterns and pitfalls

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Software · L4 · Concurrency patterns and pitfalls

Flashcards9 cards

What kind of garbage collector does Go use?1 / 9

A concurrent, tri-color mark-and-sweep collector with a write barrier. It runs mostly concurrently with the program to keep stop-the-world pauses very short (sub-millisecond), trading some throughput for low latency.

Software

GC, Memory & Performance

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GC, Memory & Performance

Quiz8 questions

Within what scope does Kafka guarantee message ordering?

AAcross the entire topic, regardless of partitionBOnly within a single partitionCOnly across the entire clusterDKafka provides no ordering guarantees at all

Software

Software · L4 · Event Streaming & Kafka

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Software · L4 · Event Streaming & Kafka

Flashcards10 cards

What does `Navigator.push` do?1 / 10

It adds a new route on top of the navigation stack, displaying the pushed screen. The previous route remains in the stack underneath.

Software

Navigation & Routing

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Navigation & Routing

Flashcards10 cards

What is a Pod in Kubernetes?1 / 10

The smallest deployable unit — one or more tightly-coupled containers sharing a network namespace (same IP) and storage. Usually one container per Pod; sidecars are the exception. Pods are ephemeral and replaced, not repaired.

Software

Kubernetes

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Kubernetes

Collection4 items

01Closures & Scope

02Prototypes & Classes

03Software · L2 · JavaScript: The Event Loop

+1 more

Software

Software · L2 · JavaScript

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Software · L2 · JavaScript

Flashcards10 cards

What is Amazon S3 and what is its core abstraction?1 / 10

S3 (Simple Storage Service) is object storage — you store files ('objects') in 'buckets', accessed by key over HTTP. It's highly durable (11 nines), scalable, and used for static assets, backups, data lakes, and static website hosting. Not a filesystem — there are no real folders.

Software

Core Services

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Core Services

Flowchart15 objects

Software

Software · L3 · Is This Function Pure?

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Software · L3 · Is This Function Pure?

Quiz5 questions

Why must you see the test fail (Red) before writing the implementation?

AIt's a formality with no practical benefitBIt proves the test actually exercises the intended behavior and would catch a regressionCFailing tests run fasterDGreen-phase code doesn't compile without it

Software

Software · L1 · Testing: The Red-Green-Refactor Cycle

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Software · L1 · Testing: The Red-Green-Refactor Cycle

Flashcards10 cards

Where does Next.js middleware run?1 / 10

It runs before a request is completed — ahead of the matched route — letting you rewrite, redirect, or set headers/cookies before the route handles the request. In Next.js 16 the file/function is renamed from middleware to proxy (proxy.ts / export function proxy()), running on the Node.js runtime; the legacy edge `middleware` name is deprecated.

Software

Middleware, Auth & Deployment

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Middleware, Auth & Deployment

Quiz8 questions

In the cache-aside pattern, what happens on a cache miss?

AThe request fails immediatelyBThe application reads from the database and populates the cache for next timeCThe cache automatically fetches from the database without application involvementDThe stale cached value is returned anyway

Software

Software · L3 · Caching Strategies

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Software · L3 · Caching Strategies

Collection2 items

01Caching & Revalidation

02Middleware, Auth & Deployment

Software

Software · L3 · Next.js

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Software · L3 · Next.js

Flowchart21 objects

Software

Software · L4 · From Alert to Root Cause Across the Three Pillars

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Software · L4 · From Alert to Root Cause Across the Three Pillars

Collection2 items

01Well-Architected & Resilience

02Multi-Account & Advanced Networking

Software

Software · L4 · AWS

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Software · L4 · AWS

Note~117 words · 1 min

Red, Green, Refactor Test-Driven Development isn't just 'write tests' — it's a specific loop, repeated for every small piece of behavior you add. Skipping the Red phase — writing the implementation before the test ever fails — means you nev

Software

Software · L1 · Testing: The Red-Green-Refactor Cycle

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Software · L1 · Testing: The Red-Green-Refactor Cycle

Note~148 words · 1 min

Match the Tool to the Coordination Problem Go's concurrency toolbox isn't one-size-fits-all. Mutexes, channels, and wait groups solve three different problems, and reaching for the wrong one usually means fighting the language instead of wr

Software

Software · L2 · Go: Choosing a Concurrency Primitive

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Software · L2 · Go: Choosing a Concurrency Primitive

Collection4 items

01Web & REST Controllers

02Spring Boot & Autoconfiguration

03Software · L2 · Spring Boot: Data Access & Transactions

+1 more

Software

Software · L2 · Spring Boot

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Software · L2 · Spring Boot

Flashcards9 cards

What is the difference between a mutex and a semaphore?1 / 9

A mutex allows exactly one thread into a critical section (binary, with ownership — only the locker can unlock). A semaphore is a counter permitting up to N concurrent accesses and has no ownership. A mutex is a specialized binary semaphore with ownership semantics.

Software

Synchronization Primitives

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Synchronization Primitives

Flowchart13 objects

Software

Software · L1 · HTML & CSS: How the Browser Renders a Page · flowchart

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Software · L1 · HTML & CSS: How the Browser Renders a Page · flowchart

Collection2 items

01State, Internals & Drift

02Module Design, Providers & Scale

Software

Software · L4 · Terraform

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Software · L4 · Terraform

Collection2 items

01Virtual Memory & Paging

02File Systems & I/O

Software

Software · L3 · Operating Systems

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Software · L3 · Operating Systems

Collection2 items

01IoC Container, Bean Lifecycle & AOP

02Transactions, Persistence & Reactive

Software

Software · L4 · Spring Boot

@openstem

Software · L4 · Spring Boot

Note~671 words · 3 min

The Three Pillars Observability tooling is usually organized around three complementary data types, each suited to a different question. Metrics are cheap, aggregatable numeric time series (counters, gauges, histograms) — great for dashboar

Software

Software · L4 · Observability: Metrics, Logs, and Traces

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Software · L4 · Observability: Metrics, Logs, and Traces

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