The chat model i'm working on deleting message for both side is what we need. What are your views about performance and possible future downsides on what you implemented? And what you recommend to use for better performance. ?

Angular is client side framework, so you cannot connect to database using angular. What you have to do is create webservices / api in any language you prefer such as: python,php or as you are using angular and you maybe more comfortable with javascript based projects,you can look into node.js + express with mysql package to connect to database and create endpoints to connect with through angular to get the data. You may have look at the link below to learn more about node.js Node.js + mysql rest api build

AWS have free tier for limited usage (maybe if you need it just for testing), Other then that if we are talking about production site then AWS costs you for what you use. You will need to understand how much CPU power, ram, storage space you need. AWS have different options for storage as well. At the end it will cost you for what you use, and amazon will ask you to add credit card in your account for billing incase you go beyond the free plan they will start adding expenses to your account and at the end of month they will charge you for what you have used such as up-time of server instance selected (price varies for types of instances), storage space used , bandwidth for outgoing and incoming. AWS does not provide an ticket support for it's basic support system, you will need to purchase an premium support from them if you need any technical help from them. If you know what you are doing with server then you are good to go (watch out the prices), you can calculate the monthly price you are going to pay from this calculator by amazon https://calculator.s3.amazonaws.com/index.html, it will give you an estimation of what you will be paying for the services you use with AWS. Digital Ocean do have different types of servers with cheap priced servers as well , which starts from $5 a month from the cheapest one (hashnode is hosted on digital ocean) and price goes up as per your need for type of server you need. Digital ocean provides very clear information regarding Pricing and type of servers based on price which you can see right here: https://www.digitalocean.com/pricing/ . All of the above are self managed servers, so you need to know how to work with servers (centos, ubuntu, debian).

This seems to be very common in companies not paying attention to codebase, i have also worked with companies in past and they also had non maintainable codebase. And i was more surprised that the creator of the system was an engineer with 10 years + experience, but when i saw his coded apps (android and ios) and webservices / web apps, the code was mess (not easily describable in few words ) Their short answer to this is : Page loads, content shows, user can use the site ? Yes ? , then its all fine codebase is not a priority and let's go ahead with adding new things in In my experience i started to care less about existing code(just give focus on security and performance) and started focusing on my new coded files to be organised and easy to edit and easily extendable code, and not to do huge changes in existing codebase until asked to do so. We should do our best to make the future of that system better and when asked start changing things in old one.

When i first started developing, i just used to not think much about anything i have had to deal with in future regarding the project and just go with anything i have had thought of for little... Now as the years been passed, i have been doing proper research about every possible functionality and stack to be used in project, and choose the right one possible, so i don't have to face much issues when managing the project and making changes into it. As we all know , first draft of project is never an end of project , there are going to be huge changes in everything possible that client can make us do. i would keep in mind about stack and way of developing the project and keep in mind about the performance, security, type of users will be using the software so everything created is basically user friendly for that kind of group (not too complex and confusing for them) ... Even if it takes week to two to me to decide the final stack for the project , i would not mind at all to proper research and take the project from a piece of paper into something functional as i would have decided the possible right stack for it and made the plans for the process and i'm good to go. But another thing i have noticed is too much of research and being double minded about multiple things , can lead to confusion for our self and make huge mistakes.

The most annoying things people say are , You are a computer guy , very easy and good life you have got , but they don't understand at all, that we guys are 24/7 into the programming, thinking always of bugs we are having , how to solve them, damnit we even dream about bugs and issues (sometimes even get the solution while we are sleeping for 5/6 hours of sleep we get) , And yeah thats really an easy and chill out life we have got :D .. They : What do you do ? Me : I'm a programmer They : What is that ? Me : We basically code create websites , mobile apps and related stuff They : Oh So why don't you make something like facebook and get famous and rich ? Me : Never Ending silence

I never had yet any horrible experience with that, but i would say that, i would for my own peace of mind , i will just run the SELECT example of DELETE query , and then be sure that it shows the result of which rows i really wanted to remove, if it's fine , then i just change SELECT * FROM to DELETE FROM ...

Your situation is same as mine... :P ... seriously need to focus just on one project then on another else they are never going to reach their end.

I have worked with many projects, but this one is the most complex and the project which really needed some serious security, The day i joined the project to revamp ... it was a serious , really serious mess , this project / web app / webservices is an project for online doctor appointment booking , patient's lifetime records, patient's medical reports , everything related to an patient , then doctor's part where doctor and it's staff is having whole part of managing their incomes , invoices, appointments and many other stuff (confidential things) , now when i open the main system core files what i see is list below : Mysql used all over the project Mysql used but not based on just single class from where it manages the connection for database , but individual mysql_query calls nearly in many files (1000+) Insert + update , any user data being submitted get's never validated and checked through to be sure if it's not something malicious File uploads , size not reduced , file type not checked , upload folder open to anyone to see all list of files in there, and execute any php file you want and delete the whole system .. meta tags , stylesheet links , everything mixed up inside <body></body> and not in head Multiple duplicate files of shared file which could have been just single file shared with others (just for sake of 1 line code ) Queries not optimised at all , (10s+ when clicked to book appointment) Subscription system based on open url where you just put an package id and thats it , you are subscribed for free without paying Full system based on spaghetti code Endless list of issues + security issues + open to any hacker attack ... it was not less them a nightmare to take all of this, and fix it's issues , remove non secure part of codes , applying validations to user's input ... Work still going on , many more issues to solve yet....

This project was fun project for me , and i just developed it in very much part time thing , it is a cloud service project, based on functionality of google drive and dropbox. Let's say , it hosts on it's own server and can be used as independent cloud service , and also you can allow your users to connect to their google and dropbox account for fast file transfers , from one to another. You can try it here : https://buckty.arshsingh.net/ username: demouser --- password: demouser It's not yet fully on the level i wanted it to be. but yet i think performs the way it should be. To few of you it might not make much feel like very high level project. But for me it was quite very interesting to make kind of functionality that it has such as : User collaborating , for sharing files and folders between users within the platform. Upload files and upload them to different folders , create folders , file informations and etc... ypu can check the demo for more detailed info. ps: it's not a promotion. thats why i'm not giving any link to the purchase page. it's just that i have worked on this and i find it interesting project on my side. :) Very soon will be working again on it , to make it node.js and mongodb based project. this was made 1 year ago. so now , would like to migrate it from php to whole node js and mongo based project with load of new things. i might release this version on github soon, as i do start from scratch to make it on node. What do you guys think? , should i make it on node js and improve more the features and security?.