curated engineering notes on algorithms, design patterns, SOLID principles, system design, and TypeScripthttps://engineering-notes.gngtgg.space/https://engineering-notes.gngtgg.space/docs/architecture/high-level-architecture/3-layered-architecture/https://engineering-notes.gngtgg.space/docs/architecture/high-level-architecture/3-layered-architecture/Separate an application into presentation, business logic, and data access layers to achieve modularity and maintainability.https://engineering-notes.gngtgg.space/docs/architecture/high-level-architecture/ddd/https://engineering-notes.gngtgg.space/docs/architecture/high-level-architecture/ddd/Domain-Driven Design is a software design approach that puts the business domain at the centre of every architectural decision.https://engineering-notes.gngtgg.space/docs/architecture/general-principles/dry-kiss-yagni/https://engineering-notes.gngtgg.space/docs/architecture/general-principles/dry-kiss-yagni/Three foundational principles that guide clean, maintainable software — avoid repetition, favour simplicity, and defer unnecessary work.https://engineering-notes.gngtgg.space/docs/architecture/general-principles/separation-of-concerns/https://engineering-notes.gngtgg.space/docs/architecture/general-principles/separation-of-concerns/Each module or component should address a single, well-defined concern.https://engineering-notes.gngtgg.space/docs/architecture/general-principles/law-of-demeter/https://engineering-notes.gngtgg.space/docs/architecture/general-principles/law-of-demeter/A method should only talk to its immediate friends, not to strangers.https://engineering-notes.gngtgg.space/docs/architecture/solid/overview/https://engineering-notes.gngtgg.space/docs/architecture/solid/overview/Five fundamental principles of object-oriented design that promote maintainable, flexible, and understandable software.https://engineering-notes.gngtgg.space/docs/architecture/solid/single-responsibility/https://engineering-notes.gngtgg.space/docs/architecture/solid/single-responsibility/A class should have only one reason to change.https://engineering-notes.gngtgg.space/docs/architecture/solid/open-closed/https://engineering-notes.gngtgg.space/docs/architecture/solid/open-closed/Software entities should be open for extension but closed for modification.https://engineering-notes.gngtgg.space/docs/architecture/solid/liskov-substitution/https://engineering-notes.gngtgg.space/docs/architecture/solid/liskov-substitution/Subtypes must be substitutable for their base types without altering program correctness.https://engineering-notes.gngtgg.space/docs/architecture/solid/interface-segregation/https://engineering-notes.gngtgg.space/docs/architecture/solid/interface-segregation/Clients should not be forced to depend on interfaces they do not use.https://engineering-notes.gngtgg.space/docs/architecture/solid/dependency-inversion/https://engineering-notes.gngtgg.space/docs/architecture/solid/dependency-inversion/High-level modules should not depend on low-level modules; both should depend on abstractions.https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/creational/singleton/https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/creational/singleton/Ensure a class has only one instance and provide a global point of access to it.https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/creational/factory-method/https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/creational/factory-method/Define an interface for creating an object, but let subclasses decide which class to instantiate.https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/creational/prototype/https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/creational/prototype/Share properties and methods among many objects of the same type through the prototype chain.https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/structural/adapter/https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/structural/adapter/Convert the interface of a class into another interface clients expect.https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/structural/proxy/https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/structural/proxy/Intercept and control interactions with target objects through an intermediate layer.https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/behavioral/observer/https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/behavioral/observer/Define a one-to-many dependency so that when one object changes state, all dependents are notified automatically.https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/behavioral/strategy/https://engineering-notes.gngtgg.space/docs/architecture/design-patterns/behavioral/strategy/Define a family of algorithms, encapsulate each one, and make them interchangeable at runtime.https://engineering-notes.gngtgg.space/docs/algorithms/sorting/quicksort/https://engineering-notes.gngtgg.space/docs/algorithms/sorting/quicksort/A divide-and-conquer sorting algorithm with average O(n log n) performance.https://engineering-notes.gngtgg.space/docs/algorithms/sorting/merge-sort/https://engineering-notes.gngtgg.space/docs/algorithms/sorting/merge-sort/A stable divide-and-conquer sorting algorithm that guarantees O(n log n).https://engineering-notes.gngtgg.space/docs/system-design/authentication/sign-in/https://engineering-notes.gngtgg.space/docs/system-design/authentication/sign-in/Designing a sign-in page with multiple authentication methods including email/password, OAuth, SSO, magic links, and passkeys.https://engineering-notes.gngtgg.space/docs/system-design/authorization/permissions/https://engineering-notes.gngtgg.space/docs/system-design/authorization/permissions/Authorization models including RBAC, ABAC, ACLs, and implementing permission systems in frontend applications.https://engineering-notes.gngtgg.space/docs/web/performance/build-pipeline/https://engineering-notes.gngtgg.space/docs/web/performance/build-pipeline/Compilers, bundlers, tree-shakers, and minifiers that turn source modules into optimized browser bundles.https://engineering-notes.gngtgg.space/docs/web/performance/loading/https://engineering-notes.gngtgg.space/docs/web/performance/loading/Techniques for delivering assets to the browser faster — compression, caching, resource hints, and media optimization.https://engineering-notes.gngtgg.space/docs/web/performance/rendering/https://engineering-notes.gngtgg.space/docs/web/performance/rendering/The steps the browser takes to turn HTML, CSS, and JavaScript into a visible web page, and what causes each step to re-run.https://engineering-notes.gngtgg.space/docs/web/performance/performance-metrics/https://engineering-notes.gngtgg.space/docs/web/performance/performance-metrics/Core Web Vitals and supporting metrics that quantify loading speed, interactivity, and visual stability in the browser.https://engineering-notes.gngtgg.space/docs/web/rendering/csr/https://engineering-notes.gngtgg.space/docs/web/rendering/csr/A rendering strategy where the server sends a minimal HTML shell and JavaScript builds the entire UI in the browser.https://engineering-notes.gngtgg.space/docs/web/rendering/ssr/https://engineering-notes.gngtgg.space/docs/web/rendering/ssr/A rendering strategy where the server generates full HTML for every request, giving the browser a complete page to display immediately.https://engineering-notes.gngtgg.space/docs/web/rendering/ssg/https://engineering-notes.gngtgg.space/docs/web/rendering/ssg/Pages are pre-rendered at build time and served as static HTML files from a CDN, giving the fastest possible time to first byte.https://engineering-notes.gngtgg.space/docs/web/rendering/isg/https://engineering-notes.gngtgg.space/docs/web/rendering/isg/An extension of SSG that regenerates individual pages in the background after deployment, keeping static performance while allowing content to update without a full rebuild.https://engineering-notes.gngtgg.space/docs/web/rendering/streaming/https://engineering-notes.gngtgg.space/docs/web/rendering/streaming/The server sends HTML in chunks as data becomes available, letting the browser start rendering before the full page is ready.https://engineering-notes.gngtgg.space/docs/web/rendering/hydration/https://engineering-notes.gngtgg.space/docs/web/rendering/hydration/A strategy that hydrates a server-rendered page in pieces — prioritizing visible or interactive sections — instead of hydrating the entire component tree at once.https://engineering-notes.gngtgg.space/docs/web/typescript/types/https://engineering-notes.gngtgg.space/docs/web/typescript/types/Quick-reference overview of TypeScript's type primitives, built-in objects, type expressions, and object type syntax.https://engineering-notes.gngtgg.space/docs/web/typescript/interface/https://engineering-notes.gngtgg.space/docs/web/typescript/interface/Defining object shapes with interfaces, extending them, and interface vs type differences.https://engineering-notes.gngtgg.space/docs/web/typescript/classes/https://engineering-notes.gngtgg.space/docs/web/typescript/classes/TypeScript class features including access modifiers, abstract classes, and implements.https://engineering-notes.gngtgg.space/docs/web/typescript/advanced-types/https://engineering-notes.gngtgg.space/docs/web/typescript/advanced-types/Covers mapped types, conditional types, and template literal types in TypeScript.https://engineering-notes.gngtgg.space/docs/web/typescript/utility-types/https://engineering-notes.gngtgg.space/docs/web/typescript/utility-types/There are a lot of utility types in Typescript that are useful for working with types.https://engineering-notes.gngtgg.space/docs/web/typescript/cfa-analysis/https://engineering-notes.gngtgg.space/docs/web/typescript/cfa-analysis/How TypeScript narrows types through control flow analysis and type guards.https://engineering-notes.gngtgg.space/docs/web/typescript/practice/typescript-challenges/https://engineering-notes.gngtgg.space/docs/web/typescript/practice/typescript-challenges/Hands-on type challenges to practice and deepen TypeScript type-level programming skills.https://engineering-notes.gngtgg.space/docs/web/react/patterns/con-pres-pattern/https://engineering-notes.gngtgg.space/docs/web/react/patterns/con-pres-pattern/Separate data-fetching and state logic from rendering logic by splitting components into containers and presentationals.https://engineering-notes.gngtgg.space/docs/web/react/patterns/hoc/https://engineering-notes.gngtgg.space/docs/web/react/patterns/hoc/Reuse component logic by wrapping components in a function that adds shared behavior.https://engineering-notes.gngtgg.space/docs/web/react/patterns/render-props/https://engineering-notes.gngtgg.space/docs/web/react/patterns/render-props/Share rendering logic between components by passing a function or component as a prop.https://engineering-notes.gngtgg.space/docs/web/react/patterns/hooks/https://engineering-notes.gngtgg.space/docs/web/react/patterns/hooks/Use state and lifecycle logic in function components without classes.https://engineering-notes.gngtgg.space/docs/web/react/patterns/provider/https://engineering-notes.gngtgg.space/docs/web/react/patterns/provider/Use React Context to share data across a component subtree without passing props through every level.https://engineering-notes.gngtgg.space/docs/web/react/patterns/compound/https://engineering-notes.gngtgg.space/docs/web/react/patterns/compound/Let related components share implicit state so they can be composed together as a single unit.https://engineering-notes.gngtgg.space/docs/web/react/releases/v18/https://engineering-notes.gngtgg.space/docs/web/react/releases/v18/Concurrent rendering, automatic batching, transitions, and new hooks landed in React 18.https://engineering-notes.gngtgg.space/docs/web/react/releases/v19/https://engineering-notes.gngtgg.space/docs/web/react/releases/v19/Actions, Server Components, the React Compiler, Activity, useEffectEvent, and more across React 19.x releases.https://engineering-notes.gngtgg.space/docs/backend/ssh-cheatsheet/https://engineering-notes.gngtgg.space/docs/backend/ssh-cheatsheet/SSH commands Cheat Sheet: ssh-keygen, ssh-copy-id, ssh-agent, authorized_keys, public key authenticationhttps://engineering-notes.gngtgg.space/docs/backend/network-tools/https://engineering-notes.gngtgg.space/docs/backend/network-tools/Basic terminal commands for checking connectivity, routes, ports, DNS records, and HTTP responseshttps://engineering-notes.gngtgg.space/docs/backend/server-setup/https://engineering-notes.gngtgg.space/docs/backend/server-setup/A cheat sheet for remote VPS setup: just a set of steps and commands to keep close for the next time I need to set it up manually.https://engineering-notes.gngtgg.space/docs/backend/nginx/https://engineering-notes.gngtgg.space/docs/backend/nginx/nginx Cheat Sheet for VPS setuphttps://engineering-notes.gngtgg.space/docs/other/terminal-basics/https://engineering-notes.gngtgg.space/docs/other/terminal-basics/Terminal Commands Cheat Sheet: pwd, cd, ls, grep, find, man, etc.