Difficult Full Stack Developer (Java) Interview Preparation Guide

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Answer it as honestly as possible. If you are keen on moving on to a managerial role, let your potential employer know that. If you want to stay in the technical field itself, make that clear too.

Every senior professional will be asked this full stack web developer interview question. Recruiters want to know if you want to stay in a technical role or would want to switch to a managerial position. They also at times might push a bit and ask if you prefer to work alone or in paired groups. It’s important, to be honest here. The company’s requirements might be different from your interests, so it is ideal that the expectations are set straight from the get-go.

This question will reveal your understanding of maintenance and code reuse, especially clean and readable code. Any aspiring full stack developer should know the principle and skill of basic prototype design, UI design, and UX design to manage different scenarios at work.

This is a typical question to understand your involvement in technology. A good way to demonstrate your involvement in continuous learning would be by speaking about the community meetups you visit. You can also talk about the webinars and the forums you regularly attend. If you have personal projects on which you apply your skills, this is a good time to showcase that as well.

Through this question, the interviewer will get an idea of how you think and work with tools. The answer should be specific and clearly state why you developed it either on front-end or back-end.

This is a moderately difficult question but a good developer would be able to get through with this in ease. An important difference between GraphQL and REST is that GraphQL doesn’t deal with dedicated resources. Everything referred to as a graph is connected and can be queried to app needs.

A person who loves technology is always working with it. Whether it be for your company or for your own recreational reasons. Good programmers will always have something to share. Candidates who code willingly for personal learnings will always stand out here.

final is a Java keyword used to indicate that either a method can not override in a subclass, or a class can not be extended or a field can not be modified. finalize is a method that gets called on an instance of an Object when it is garbage collected. finally is a Java keyword used in exception handling to indicate a block of code that should always be run whether an exception is thrown or not.

☛ 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?

This question is used to probe the authenticity of the information you furnished in your last question. It is important that you are aware of the latest in the industry and have a pulse of what’s happening. You might talk about a website that you tested recently, or talk about an obnoxious case study about a serious bug you recently read about. A point to note, never give the interviewer an impression that you have learned nothing in the past 6 months. This is a fast-changing tech game, and being up-to-date with the current trends is an absolute must.

This question is very commonly asked to check the candidate’s understanding of design patterns. It is a broad term but is more specifically used by software developers for describing a pattern which is used to decouple layers and components in a system.

Working at your job will not always boost your learning curve. Any aspiring developer should try and implement codes on their personal projects that include website development. Remember, a self-motivated coder might have several projects to experiment and learn. Hiring managers are constantly looking for candidates who enjoy the whole process of web development.

The JIT is the JVM’s mechanism by which it can optimize code at runtime.

JIT means Just In Time. It is a central feature of any JVM. Among other optimizations, it can perform code inlining, lock coarsening or lock eliding, escape analysis etc.

The main benefit of the JIT is on the programmer’s side: code should be written so that it just works; if the code can be optimized at runtime, more often than not, the JIT will find a way.

Node.js is a single threaded application but it support concurrency via concept of event and callbacks. As every API of Node js are asynchronous and being a single thread, it uses async function calls to maintain the concurrency. Node uses observer pattern. Node thread keeps an event loop and whenever any task get completed, it fires the corresponding event which signals the event listener function to get executed.

It isn’t accurate because it will only account for the number of characters within the String. In other words, it will fail to account for code points outside of what is called the BMP (Basic Multilingual Plane), that is, code points with a value of U+10000 or greater.

The reason is historical: when Java was first defined, one of its goal was to treat all text as Unicode; but at this time, Unicode did not define code points outside of the BMP. By the time Unicode defined such code points, it was too late for char to be changed.

☛ Maintain a code repository
☛ Automate the build
☛ Make the build self-testing
☛ Everyone commits to the baseline every day
☛ Every commit (to baseline) should be built
☛ Keep the build fast
☛ Test in a clone of the production environment
☛ Make it easy to get the latest deliverables
☛ Everyone can see the results of the latest build
☛ Automate deployment

HTTP/2 provides decreased latency to improve page load speed by supporting:

☛ Data compression of HTTP headers
☛ Server push technologies
☛ Loading of page elements in parallel over a single TCP connection
☛ Prioritization of requests
An important operational benefit of HTTP/2 is that it avoids the head-of-line blocking problem in HTTP 1.

Speak about the most recent bug or a discrepancy you came across and explain how you went ahead to overcome it. Tell the interviewer that you are a person who believes in collaborative work. Depict how you could solve the issue with the help of a colleague, online community or your mentor. It is always good to ask when you don’t know.

This is a tricky one… it doesn’t! Garbage Collection simply cleans up unused memory when an object goes out of scope and is no longer needed. However an application could create a huge number of large objects that causes an OutOfMemoryError.

This is a tricky question. This will actually give the hiring manager an idea of both the complexity and the style of projects you have done in the past. You should explicitly mention the issues you faced and the measures you took to overcome that roadblock. You can additionally speak about the learnings you earned from the issue.

This question is asked to find out how involved or uninvolved a candidate is in the technology community. Interviewees should respond by describing a few meetups they are part of related to JavaScript, or personal projects that they have displayed in GitHub

The main and most important difference between REST and GraphQL is that GraphQL is not dealing with dedicated resources, instead everything is regarded as a graph and therefore is connected and can be queried to app exact needs.

☛ 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?

An ETag is an opaque identifier assigned by a web server to a specific version of a resource found at an URL. If the resource content at that URL ever changes, a new and different ETag is assigned.

In typical usage, when an URL is retrieved the web server will return the resource along with its corresponding ETag value, which is placed in an HTTP “ETag” field:

ETag: "unique_id_of_resource_version"
The client may then decide to cache the resource, along with its ETag. Later, if the client wants to retrieve the same URL again, it will send its previously saved copy of the ETag along with the request in a "If-None-Match" field.

If-None-Match: "unique_id_of_resource_version"
On this subsequent request, the server may now compare the client’s ETag with the ETag for the current version of the resource. If the ETag values match, meaning that the resource has not changed, then the server may send back a very short response with a HTTP 304 Not Modified status. The 304 status tells the client that its cached version is still good and that it should use that.

However, if the ETag values do not match, meaning the resource has likely changed, then a full response including the resource’s content is returned, just as if ETag were not being used. In this case the client may decide to replace its previously cached version with the newly returned resource and the new ETag.

This is a hypothetical question geared at understanding the level at which the hiring manager will gauge your readiness to start the job. It is an easy way to distinguish a good full stack developer from someone who is an amateur. People who have difficulty transmitting their thoughts will have bleak chances of getting through at this point.