Full-Stack Developer Interview Questions & Answers

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When a program contains two conflicting accesses that are not ordered by a happens-before relationship, it is said to contain a data race. Two accesses to (reads of or writes to) the same variable are said to be conflicting if at least one of the accesses is a write

The result of any execution is the same as if the operations of all the processors were executed in some sequential order, and the operations of each individual processor appear in this sequence in the order specified by its program

A memory barrier, also known as a membar, memory fence or fence instruction, is a type of barrier instruction that causes a CPU or compiler to enforce an ordering constraint on memory operations issued before and after the barrier instruction

Deadlock is a situation in which two or more competing actions are each waiting for the other to finish, and thus neither ever does. A livelock is similar to a deadlock, except that the states of the processes involved in the livelock constantly change with regard to one another, none progressing.

Contention is simply when two threads try to access either the same resource or related resources in such a way that at least one of the contending threads runs more slowly than it would if the other thread(s) were not running. Contention occurs when multiple threads try to acquire a lock at the same time

A program is correctly synchronized if and only if all sequentially consistent executions are free of data races. Correctly synchronized programs have sequentially consistent semantics. Causality requirement for incorrectly synchronized programs.

Behavior of software system where the output is dependent on the sequence or timing of other uncontrollable events

The MEAN (MongoDB, Express, AngularJS, and Node.js) stack is the most popular open-source JavaScript software stack available for building dynamic web apps—the primary advantage being that you can write both the server-side and client-side halves of the web project entirely in JavaScript. Even if you aren’t intending to use MEAN for your project, you can still learn a lot about the developer when they recount their experiences using JavaScript for different aspects of web development.

Threads (of the same process) run in a shared memory space, while processes run in separate memory spaces

Each object in Java is associated with a monitor, which a thread can lock or unlock

Growing phase, shrinking phase. Guarantees serializablity for transactions, doesn't prevent deadlock

A full stack developer is sure to have a lot to talk about here. There are many technologies and programming languages today, pick one from each category that you are strongest at.

Client side technologies: Javascript, CSS, jQuery, HTML, SAAS

Client Side framework: AngularJS, BackboneJS, ember.js, React, Metoe, Polymer

You need not worry your head with all the javascript frameworks available in the market. Just have a good command over one or two of them and you are good to face the interview. It takes less than two days to understand a new framework.

Server Side Technologies: Web API, Java API, Entity framework, ruby and rails, MVC, WCF, Python, node.js are some server side technologies. You need to be either a part of Java family or .Net family or completely the latest JavaScript and Node.js server side. The main role of a developer in the server side is to develop Web APIs that provide data to client application. Therefore, having a strong command in at least one of the technologies in order to develop the API is essential.

Database: MongoDB, SQL Server, Oracle, POstgreSQL etc.

Functional programming is one of the key paradigms that makes JavaScript stand out from other languages. Look for examples of functional purity, first-class functions, higher-order functions, or using functions as arguments and values. It’s also a good sign if they have past experience working with functional languages like Lisp, Haskell, Erlang, or Clojure.

☛ What is your total experience?
☛ Have you ever worked with web applications? Describe the projects.
☛ Did you ever have problematic situations or conflicts when fulfilling the task? Describe them.
☛ What software, technologies and/or tools did you use in your previous projects?
☛ What are your expectations as to the opened position?
☛ How can you define such terms as inversion control, virtual function, and dynamic bidding?
☛ How can you define tail recursion?
☛ Describe the working process of the garbage collector. What’s it like?
☛ What is A/B testing and when it is applicable?
☛ What design principles do you know?
☛ If separation of concerns is not used in development, what will be the drawbacks to your mind?
☛ What are the pros of microservices?
☛ What is 3-tier architecture?
☛ What is 3-layer architecture?
☛ Why use an application server? What is it for?
☛ How do you understand the aspect-oriented programming?

Can be safely invoked by multiple threads at the same time

REST stands for Representational State Transfer, an architectural style that has largely been adopted as a best practice for building web and mobile applications. RESTful services are designed to be lightweight, easy to maintain, and scaleable. They are typically based on the HTTP protocol, make explicit use of HTTP methods (GET, POST, PUT, DELETE), are stateless, use intuitive URIs, and transfer XML/JSON data between the server and the client.

Var emptyArray = [‘this’, ‘array’, ‘is’, ‘full’];
This deceptively simple question is designed to test your prospective coder’s awareness of mitigating potential bugs when solving problems. The easiest method would be to set “emptyArray” equal to “[ ]”—which creates a new empty array. However, if the array is referenced anywhere else, the original array will remain unchanged. A more robust method would be “emptyArray.length – 0;”—which not only clears the array but updates all reference variables that point to this original array. Some possible solutions are listed below:

emptyArray.length = 0;
emptyArray.splice(0, emptyArray.length);
while(emptyArray.length){
emptyArray.pop();
}
emptyArray = []

The great thing about JavaScript is the ability to do away with the rigid rules of classical inheritance and let objects inherit properties from other objects.

☛ Classical Inheritance: A constructor function instantiates an instance via the “new” keyword. This new instance inherits properties from a parent class.
☛ Prototypal Inheritance: An instance is created by cloning an existing object that serves as a prototype. This instance—often instantiated using a factory function or “Object.create()”—can benefit from selective inheritance from many different objects.

console.log(0.1 + 0.2);
console.log(0.4 + 0.1 == 0.5);

This is a trick question in that at first glance, you might expect the console to print out “0.3” and “true.” The correct answer is that you can’t know for sure, because of how JavaScript treats floating point values. In fact, in the above example, it will print out:

0.30000000000000004
false

var lorem = { ipsum : 1};
var output = (function(){
delete lorem.ipsum;
return lorem.ipsum;
})();

console.log(output);
The output would be undefined, because the delete operator removed the property “ipsum” from the object “lorem” before the object was returned. When you reference a deleted property, the result is undefined.

This question may seem self-explanatory, but what you’re looking for is a developer who can demonstrate solid understanding of how data flows throughout the application. In two-way data binding, changes to the UI and changes to the model occur asynchronously—a change on one end is reflected on the other. In one-way data binding, data only flows one way, and any changes that the user makes to the view will not be reflected in the model until the two are synced. Angular makes implementing two-way binding a snap, whereas React would be your framework of choice for deterministic one-way data flow.

Prototypal OO is the other major programming paradigm that really lets JavaScript shine—objects linked to other objects (OLOO). You’re looking for knowledge of when and where to use prototypes, liberal use of “Object.assign()” or mixins, and a solid grasp of concepts like delegation and concatenative inheritance.

You want a developer who really knows how to play to the strengths of your chosen platform. Some key advantages of JavaScript are listed below for your convenience.

☛ Lightweight: JavaScript can be executed within the user’s browser without having to communicate with the server, saving on bandwidth.
☛ Versatile: JavaScript supports multiple programming paradigms—object-oriented, imperative, and functional programming and can be used on both front-end and server-side technologies.
☛ Sleek Interactivity: Because tasks can be completed within the browser without communicating with the server, JavaScript can create a smooth “desktop-like” experience for the end user.
☛ Rich Interfaces: From drag-and-drop blocks to stylized sliders, there are numerous ways that JavaScript can be used to enhance a website’s UI/UX.
☛ Prototypal Inheritance: Objects can inherit from other objects, which makes JavaScript so simple, powerful, and great for dynamic applications.

Specification describes a modular system and a service platform for the Java programming language that implements a complete and dynamic component model. Each bundle has its own classpath. Dependency hell avoidance. META-INF/MANIFEST.MF contains OSGI-info

Variable of type Shape could refer to an object of type Square, Circle... Ability of a function to handle objects of many types