Step 1: Initialize Project

mkdir ts-node-server && cd ts-node-server npm init -y npm install express npm install --save-dev typescript ts-node @types/node @types/express

to generate js file https://www.bacancytechnology.com/qanda/node/watch-and-reload-ts-node-when-typescript-files-change

GIT:- Types script:- Git new type script change:- https://github.com/fifocode/nodejs-backend-architecture-typescript/tree/main MERN TypeScript Food Ordering App https://github.com/Rakesh-99/restaurant-management-and-food-ordering-platform/tree/master Normal:- Source code of Food order website built with MongoDB, Express, React JS and Node JS https://github.com/aayushai/Hangry/tree/main https://github.com/ayushnighoskar/FoodDeliveryApp

Node validation:- https://www.youtube.com/watch?v=QR-oi1PCaZk

------------------------Question:----------------- https://www.geeksforgeeks.org/node-interview-questions-and-answers/

What is REPL in NodeJS? What is REPL in NodeJS? What do you mean by event loop in NodeJS? What is control flow in NodeJS? 24. What is event-driven programming in NodeJS? 25. What is a buffer in NodeJS? 26. What are streams in NodeJS? Transform Streams: 27. Explain the crypto module in NodeJS. 28. What is callback hell? 29. Explain the use of the timers module in NodeJS. 30. Difference between setImmediate() and process.nextTick() methods 44. What is a cluster in NodeJS? 60. What is an Event Emitter in Node.js? what is option/ferflight in context of rest api https://www.youtube.com/watch?v=tcLW5d0KAYE what is assyncHandler or high-order-function https://www.youtube.com/watch?v=wiOvFcvL6vQ What is reader board or priority queue what is high-order-function functionality like asyncHandler in ENV file all data comes as string if type number is required then it need to convert to number when node server is created at that time all midleware function is loaded once for that log is no printed to print it every time for that for that you need to return request response file microservices\identity-service\src\middlewares\rateLimit.middleware.js To print the stack of error you need to snd the error microservices\api-gateway\src\server.js -> (logger.error(proxyErrorHandler:- ${err});) why on some case arrow function doesn't work we have to define function line bind on setTimeout -> chatgpt Difference between var let and const -> chatgpt can get direct declared value inside seTimeout we need to bind() or use promise microservices\identity-service\src\controllers\user.controller.js what is singleton connection connection what is nginx reverse proxy

------------------------Question:-----------------

https://www.youtube.com/watch?v=_f7h6xQXiLA&list=LL&index=4&t=1126s Social media microservice - https://github.com/sangammukherjee/Nodejs-microservices-2025 Express & Redis - https://github.com/sangammukherjee/NodeJS-Express-Redis-Concepts-2025 section 1 how event loop works

        1. timers
            Execute the callbacks schedule by set-time-out or set-interval
                After that it run all pending call back
                After that ideal and prepare
                after that pool which retrieve new input out put events
                After that CHECK set immediate call back
                Then close callback
        2.Microtask which execute immediately after the current operation complete
            EX:- process.nextTick, promises , object.observe
        2. Macrotask it execute on next iteration of event loop
            Ex:- setTimeOut, SetImmediate, setImmediate, Input/output operation(Like file read)

        Phase of execution :-
            timers -> pending callback -> ideal , prepare (this is handle by node) -> poll -> check -> close callback

    buffers
        It's use for handel binary data
            Ex:- Uploading file, image and also in case of cryptography
    what is concepts of streams and worker threads
        there is 4 type of streams 35:00
            writable
            readable
            duplex -> for both read and write
            transform ->

    Cors  this is use to configure cross origin  45:00
    MiddleWare/errorHandler/assyncHandler or high-order-function functionality 1:00 Hr
    express-rate-limit this is use to restrict user to trigger api multiple time 1:23 Hr
    API versioning how api versioning is done 1:21
    to print all request log track 1:33:28
    error handling 1:36
    radish cache it's a remote dictionary server it's a in-memory(it's store data in memory) database 1:40
        read/write operation
        persistence it will set data for a duration
        it support multiple datastructure
        it also help us on pub/sub it enable real time communication between client
        cashing/session management
        realtime analytic

        Datastructure 1:59

        LIST ->         2.04.07
            LPUSH (it push at the beginning of the list ) RPUSH (it push at the end of the list)
            LRange retrive element form the specific range
            LPOP it will remove and retrieve first element of the list from left side
            RPOP it will remove and retrieve last element of the list from right side

        SETS -> 2:10:25
            SADD this will all one or more member to a set
            SMEMBERS -> It will return all the element of a set
            SISMember -> To check particular member exist in a set
            SREM -> remove one or more item from the set
            sorted sets -> is sorted-set each element has a score associated to it it is use on reader board or priority queue
                ZADD -> add element with score
                ZRANGE -> retrive renge of element
                ZRANK -> this will give rank of element or position sorted set
                ZREM -> remove one or more element

        Hashes 2:22:48
            HSET to set the value  this is like map.set map.value
            HGET to get the value
            HGETALL to get all the value
            HDELETE to delete

        Pub/Sub 2:27
            publisher -> send -> chanel -> subscriber will consume that
                Publisher will send message to chanel and subscriber will consume that.

        Pipelining and transaction 2:36:53
            Pipelining is the process of sending multiple commend in a batch
            transaction is a process in which multiple command are executed as a single unit


    Microservice 2:58
        Identity Service
            server.js file on identity-service 3:55
            print log for request response 3:58
            rate Limit (rate-limiter-flexible)  3:59
                RedisClint
                DDOS protection and rate limit :4:01:51

            Express-rate-limit 4:06:03
            unhandledRejection 4:14:12
        API gateway 4:20
            env file creation
            server.js file 4:24:44
            proxy service work 4:29
                setup proxy for authentication route 4:36:13
        Post-service 5:15
            npm i nodemon --save-dev 5:18:40
            IP base ratelimit for sensitive end points 5:42:12
            assigning user-id on header 5:46:12
            getAllPost DeletePost getPost for invalid cache/cache-work 6:03
                invalid cache 6:13
        Media-service 6:38
        RabbitMQ 7:17
        search service 8:05
            search delete data if post deleted 8:38
        Docker work 8:50
        VPS hosting 9:14
            Remote - SSH to connect remote ssh with VS code 9:27
        CI CD deployment process 9:43

https://github.com/goldbergyoni/nodebestpractices https://github.com/ryanmcdermott/clean-code-javascript https://github.com/strapi/strapi CMS https://github.com/getify/You-Dont-Know-JS https://github.com/SheetJS/sheetjs https://github.com/ExpressGateway/express-gateway