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Software: explore STEM content (page 22 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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Flowchart17 objects

Software

Software · L3 · Choosing a Caching Strategy

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Software · L3 · Choosing a Caching Strategy

Flowchart9 objects

Software

Software · L1 · Spring Boot: Application Lifecycle & Logging · flowchart

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Software · L1 · Spring Boot: Application Lifecycle & Logging · flowchart

Note~657 words · 3 min

The Service Mesh As the number of services grows, cross-cutting network concerns — mTLS, retries, timeouts, load balancing, circuit breaking, traffic splitting for canaries — become repeated work in every service's code. A service mesh move

Software

Software · L4 · Microservices Architecture & Resilience Patterns

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Software · L4 · Microservices Architecture & Resilience Patterns

Flashcards10 cards

What three properties make up the CIA triad?1 / 10

Confidentiality (only authorized parties can read data), Integrity (data isn't tampered with undetected), and Availability (systems and data are accessible when needed). It's the core model for evaluating security.

Software

Security Fundamentals

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Security Fundamentals

Quiz10 questions

Which HTTP status code means 'a new resource was created'?

A200 OKB201 CreatedC204 No ContentD301 Moved Permanently

Software

Software · L4 · HTTP & REST — 10 Q

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Software · L4 · HTTP & REST — 10 Q

Flowchart13 objects

Software

Software · L5 · Chomsky Hierarchy

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Software · L5 · Chomsky Hierarchy

Flashcards10 cards

What are HotSpot's C1 and C2 compilers in tiered compilation?1 / 10

C1 (client) compiles quickly with light optimization for fast warm-up; C2 (server) applies aggressive, profile-guided optimizations for peak throughput on hot methods. Tiered compilation starts interpreted, moves to C1, then promotes the hottest code to C2.

Software

JVM Internals & Performance

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JVM Internals & Performance

Flashcards10 cards

What is a factory constructor used for?1 / 10

It is a constructor that does not always create a new instance: it can return a cached object, a subtype, or run logic before returning. It must return an instance of the class.

Software

OOP, Classes & Mixins

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OOP, Classes & Mixins

Quiz8 questions

Which observability pillar is best suited to answering 'where in a multi-service call chain did the time go?'

AMetricsBLogsCTracesDNone of them can answer this

Software

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

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

Note~125 words · 1 min

Three Kinds of Storage Like most cloud providers, GCP splits storage by access pattern. Cloud Storage holds objects accessed over HTTP(S) with no real filesystem. Persistent Disk is a block device attached to one VM at a time. Filestore is

Software

Software · L1 · Google Cloud: Storage & Database Options

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Software · L1 · Google Cloud: Storage & Database Options

Flashcards10 cards

What is the React Fiber architecture?1 / 10

Fiber is React's internal reconciler (introduced in React 16). Each React element is a fiber node — a unit of work with priority, parent/sibling/child links. Fibers allow work to be paused, resumed, or aborted, enabling concurrent rendering.

Software

Concurrent React & Internals

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Concurrent React & Internals

Flashcards9 cards

What is the primary role of an operating system?1 / 9

The OS manages hardware resources (CPU, memory, storage, devices) on behalf of programs and provides a clean abstraction layer — processes, files, sockets — so applications don't program hardware directly.

Software

OS Fundamentals

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OS Fundamentals

Note~135 words · 1 min

Three Kinds of Storage AWS offers storage shaped for different access patterns. Object storage (S3) is accessed over HTTP and has no real filesystem. Block storage (EBS) behaves like a virtual hard disk attached to one instance. File storag

Software

Software · L1 · AWS: Storage Options Compared

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Software · L1 · AWS: Storage Options Compared

Collection2 items

01Dynamic Programming

02Graphs & Traversals

Software

Software · L3 · Data Structures & Algos

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Software · L3 · Data Structures & Algos

Flowchart11 objects

Software

OOP & Collections · flowchart

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OOP & Collections · flowchart

Flashcards9 cards

What is sound null safety in Dart?1 / 9

Types are non-nullable by default; you must explicitly opt in with `?` (e.g. String?) to allow null. The compiler guarantees a non-nullable variable can never be null, eliminating null-reference errors at compile time. Introduced in Dart 2.12 and made mandatory (no opt-out) in Dart 3.0.

Software

Language Basics

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Language Basics

Flashcards10 cards

What does `strict: true` enable in tsconfig?1 / 10

It enables a suite of strict checks: `strictNullChecks`, `strictFunctionTypes`, `strictBindCallApply`, `strictPropertyInitialization`, `noImplicitAny`, `noImplicitThis`, `alwaysStrict`. Strongly recommended.

Software

Compiler & Config

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Compiler & Config

Flashcards10 cards

How does JavaScript's garbage collector know when to free memory?1 / 10

Modern engines use mark-and-sweep: the GC marks all objects reachable from GC roots (globals, call stack), then sweeps (frees) everything unreachable. Objects not reachable from any live reference are eligible for collection.

Software

Performance & Memory

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Performance & Memory

Collection5 items

01Goroutines & Channels

02Types & Interfaces

03Errors & Idioms

+2 more

Software

Software · L2 · Go

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Software · L2 · Go

Note~112 words · 1 min

Three Ways to Create a Value Go gives you three different ways to bring a value into existence, and they aren't interchangeable — each is scoped to a different kind of type or a different need. Picking One In practice, most Go code reaches

Software

Software · L1 · Go: new(), make(), or a Literal?

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Software · L1 · Go: new(), make(), or a Literal?

Note~840 words · 4 min

Finite Automata and Regular Languages A deterministic finite automaton (DFA) is a 5-tuple M = (Q, Σ, δ, q₀, F): a finite state set Q, alphabet Σ, total transition function δ: Q × Σ → Q, start state q₀, and accepting states F ⊆ Q. Extend δ t

Software

Software · L5 · Automata Theory & Formal Languages

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Software · L5 · Automata Theory & Formal Languages

Flashcards10 cards

What do the letters in the STRIDE threat model stand for?1 / 10

Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, and Elevation of privilege — a taxonomy for enumerating threats against each component and data flow.

Software

Threat Modeling & Zero Trust

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Threat Modeling & Zero Trust

Flashcards8 cards

Why do you need a stable `key` when rendering a list?1 / 8

Keys let React match elements between renders to reuse DOM nodes and preserve component state. Using array index as key breaks when items are reordered/inserted — state attaches to the wrong item.

Software

Rendering & Reconciliation

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Rendering & Reconciliation

Flashcards9 cards

What is the main weakness of range-based sharding?1 / 9

Range sharding (e.g. splitting by user ID range) preserves ordering and makes range queries efficient, but concentrates writes onto whichever shard owns the currently 'hot' range — e.g. all new signups land on the last shard if sharded by monotonically increasing ID, creating a hotspot.

Software

Data Partitioning & Replication at Scale

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Data Partitioning & Replication at Scale

Collection2 items

01Memory & Smart Pointers

02Concurrency & Async

Software

Software · L3 · Rust

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Software · L3 · Rust

Flashcards10 cards

What do the `Send` and `Sync` marker traits guarantee?1 / 10

`Send` means a type can be transferred across thread boundaries; `Sync` means `&T` can be shared across threads safely. The compiler uses them to enforce data-race freedom.

Software

Concurrency & Async

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Concurrency & Async

Flashcards10 cards

What is the primary purpose of a VPC?1 / 10

A VPC is a logically isolated virtual network within an AWS region where you launch resources, controlling IP addressing, subnets, routing, and gateways.

Software

Networking & VPC

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Networking & VPC

Collection2 items

01TLS & HTTPS

02WebSockets & Real-time

Software

Software · L3 · Networking & HTTP

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Software · L3 · Networking & HTTP

Collection4 items

01Rendering & Routing

02Next.js Fundamentals

03Software · L1 · Next.js: Images, Fonts & Assets

+1 more

Software

Software · L1 · Next.js

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Software · L1 · Next.js

Flashcards10 cards

What is the core idea of a service mesh?1 / 10

A service mesh moves cross-cutting networking concerns (mTLS, retries, timeouts, traffic shifting, telemetry) out of application code into a sidecar proxy (data plane) per Pod, controlled by a central control plane. Apps stay oblivious to the L7 logic.

Software

Service Mesh & GitOps

@openstem

Service Mesh & GitOps

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