Interviewing the Full Stack Developer: Role Matters

A Full Stack Developer can step into a critical niche in almost any company in the world of software programming. That’s because the Full Stack Developer’s “specialty” is to be the team’s generalist.

The role requires the ability to work both in the Back End—the server side—and the Front End—the client side or user interface. A Full Stack Developer gives different teams flexibility. A very small team developing a limited application may require a Full Stack Developer who can handle everything—the “full stack” from Back End to Front End. On a larger team, the Full Stack Developer might have a swing role, helping both the Back End and Front End as well as checking the complete functionality of the project and enhancing communication across all team members.

Full stack developer interview questions

In a job interview, a Full Stack Developer will often be asked:

  1. What languages can you use to code? Front End development, with interface and user-interface systems such as navigation and visuals, may use HTML, CCC3, and JavaScript. Back End development working with the server and database that will support the Front-End application may use Python, Ruby, and PHP.  In order to check the accuracy and functionality of the full stack, and especially the Front-Back connection, the Full Stack Developer has to know both sets of languages as well as MySQL and machine learning.
  2. On software development teams, are you used either on the Front End or Back End—or assigned to take responsibility for the entire experience of the full stack? Some teams use the Full Stack Developer to fill whatever role is needed (Back End or Front End); other teams want to have a permanent multitasker looking at everything.
  3. On your present development team, do you play a major role in communicating between team members on the Back End and Front End?

There are also common Full Stack Developer interview questions and answers for experienced engineers. These candidates might be asked:

  1. Have you been given responsibility for testing and debugging software to keep it up-to-date for the web application?
  2. How do you help to ensure cross-platform compatibility and optimization?
  3. How have you kept up with technological advances to optimize software?

GitHub lists dozens of areas in which a candidate for Full Stack Developer might be questioned. You’ll find these examples just under the category Quality Assurance:

  1. What is unit test? (Aimed at a single unit of functionality)
  2. What is component test?
  3. What is integration test? (Making sure that when integrated, several parts of a system work as expected)
  4. What is user acceptance test? BDD?
  5. Unit tests advantages
  6. Types of tests (Acceptance testing, functional testing, smoke testing, regression testing, unit testing, integration testing, stress testing, load, performance, sanity, stability, security, feature, progression, installation, business)
  7. Differences between stub and mock (A stub is a test double with preprogrammed behavior. Mocks are stubs with preprogrammed expectations)
  8. Selenium tests and web-driver
  9. How to test multithreading code

This Full Stack Developer interview questions and answers pdf with the full spectrum of areas is available to download.

Full stack developer coding test

HR personnel and engineers usually interview candidates for the position of Full Stack Development by asking about degrees and certifications, work experience, coding and other skills, and specific job challenges and achievements. In the end, however, your company is going to have to decide if a candidate has the specific coding skills, problem-definition skills, and problem-solving skills needed by the development team working on your company’s most important challenges.

Online coding challenges provide objective evidence of the candidate’s performance in using code to define and provide solutions to real-life problems. Woven’s online coding test is role-based, so that skills tested are those required by the Full Stack Developer.  (Our testing addresses nine major roles in software development, systems architecture, and debugging, but custom tests for other roles can be created.)

An example of the outstanding value of the online coding test for Full Stack Developer would be engaging the software programming languages required in the Front-End role (e.g., JavaScript), the Back-End role (e.g., Python), and cross-disciplinary role (MySQL).

But many programmers begin by learning a language like C##, so a less senior or a beginning Full Stack Developer position might have Full Stack Development C# questions like these:

  • What is an Object?
  • What is the difference between “continue” and “break” in C#?
  • How is “Exception Handling” implemented in C#?
  • What are dynamic type variables in C3?
  • What is boxing and unboxing?

Junior full stack developer interview questions

Those are just a few examples of questions that might pertain to the Full Stack Developer role in one area. Woven online coding tests are available not only for the role of Junior/Mid Fullstack Engineer, but also Mid/Senior Fullstack Engineer, Engineering Manager, Mid/Senior Frontend Engineer, and five other core roles on the software development team.

For example, the online coding challenge for the Junior/Mid Fullstack Engineer would engage the role’s relevant capabilities in debugging, technical communication, systems thinking, Back-End Programming, and Front-End Programming. It also seeks evidence that the candidate can debug web applications and identify when to ask for help in doing so. With guidance, can the candidate write both Front-End and Back-End code that is correct and clear?

Full Stack CafĂ© lists 50 interview questions that a Junior Web Developer/Junior Full Stack Developer “can’t miss.”  Here are a dozen examples:

  • Explain “equality” in JavaScript.
  • Explain meta tags in HTML.
  • What is CSS?
  • Explain three ways to apply CSS styles to a web page.
  • What is Git?
  • What is Node.js?
  • What is SQL injection?
  • What is “scope” in JavaScript?
  • What is meant by “continuous integration”?
  • What is npm?
  • Describe “floats” and how they work.
  • Describe what “user interface design” means for you.

Check out this Junior Software Developer questions and answers pdf for even more examples.

GitHub questions for full stack developers

GitHub is the largest and most advanced platform in the world where developers and companies build and maintain their software. It’s used by more than 65 million developers and more than three million organizations, and it’s the repository of more than 200 million software versions. “Git” is a free and open-source distributed version-control system for files. It is used for version control of files for projects of all sizes.

Offering software developers “everything in one place,” GitHub has the biggest hand-picked collection of top technical interview questions for both junior and experienced Full Stack Developers and other web developers. Given the Front End and Back End responsibilities, it includes questions in Java and Python, for example, because different programming languages are favored by user interface developers (Front End) and server and data developers (Back End).

Java is widely used by developers because it is platform independent, meaning that its programs run on different types of computers (if they have a Java Runtime Environment.) Most types of computers are compatible with JRE, including PC for Windows, Macintosh, Unix, or Linux. So are mobile phones. Also, given its early entry into the field, Java language is now built into the systems of banks, retailers, insurance companies, and utilities worldwide.

Java programming language combines a very simple coding language with a library of the most common utility functions that Java programs must have. Java API is its class library and inseparable from the language itself; learning API is at least half the challenge of learning Java because API has thousands of classes and even more methods of using them in programs.

Github offers questions for developers in Java in dozens of categories. Here are examples of interview questions about Java 8:

  • What are the important features of Java 8 release? (There is a list of about two dozen features)
  • Can you declare an interface method static? (Java makes possible static methods at interfaces)
  • What is lambda? (A set of instructions that can be repeatedly called in a program)
  • What variables do lambda expressions have access to? (Immutable variables, class fields, and static variables)
  • What is a method reference? (If the method existing in a class does all that is necessary, then simple reference to the method will repeat the result elsewhere)
  • What types of method reference do you know? (They include the static method, the per instance method, and to the constructor)

Github offers examples of questions, compiled by hundreds of developers, for the Front End Developer interview. These are some from the category “general questions”:

  • Why has it traditionally been better to serve site assets from multiple domains?
  • Do your best to describe the process from the time you type in a website’s URL to its finishing loading on your screen.
  • What are the differences between “Long Polling,” “Websockets,” and “Server Sent” events?
  • Explain the following request and response headers:
  • Between Expires, Dates, Age and If-Modified…
  • Do Not Track…
  • Cache-Control…
  • Transfer-Encoding…
  • ETag…
  • X-Frame Options…
  • What are HTTP methods? List all HTTP methods that you know and explain them.
  • What is domain prefetching and how does it help with performance?
  • What is a CDN and what is the benefit of using one?

Cracking the Coding Interview

The 6th edition of Cracking the Coding Interview: 189 Programming Questions and Solutions by Gayle Laakmann Mcdowell, has been described as “two books.” (Here is a Cracking the Coding Interview pdf from Github.)

Most of the book is devoted to the programming questions and solutions based on algorithm, coding, and design with a walk-through for each solution. (By the way, the vast majority of the coding problems in the books are written in Java.)

But it begins with about 100 pages devoted to what to expect during the interview and how to prepare for it. The author was on the hiring review board at Google, where she hired hundreds of software engineers, and gives insights into the hiring process at Amazon, Facebook, and other giants.

The newest edition of Cracking the Coding Interview has raised many questions among both job candidates and interviewers. A strong point of the book is a consistent effort to get candidates ready to think and problem-solve—both to prepare for the interview and to succeed during it. However, many candidates are concerned that they are given a long list of problems to solve without the coding tools they ordinarily use to solve them.

Candidates are asked to do whiteboard work (visualize thoughts and concepts, write down ideas, plan and create) that they might not do on a daily basis—or ever—in their particular roles in software development (for example, Back End Developer versus a Front End Developer versus a Full Stack Developer). The same can be said for presenting virtually all problems in Java, a programming language favored for Front End Developers, though very widely used.

Candidates for a role like Full Stack Developer, with almost all the book’s problems in Java, would not face the real-life situation of a role requiring familiarity with the chief Back End programming languages, the chief Front End programming languages, and specialized languages like MySQL.

The Woven online coding challenge

Woven creates online coding tests that place candidates in a real-life problem-solving situation they would face in a particular role (Full Stack Engineer), at a particular grade (junior/mid, mid/senior), at a company like the one recruiting them. One key to this real-life concept of testing is our role-based coding challenges as described earlier.

Of course, no test perfectly captures the capabilities required for success on a given team. But, our approach at Woven takes account of programming languages associated with different roles. We understand coding tools that are part of the work environment for software developers in different roles.

When asked about Cracking the Coding Interview, job candidates have said that “right or wrong” scoring of some tests entrenches preferred answers. Because Woven’s online coding challenges are scored by at least two senior engineers and not an “answer sheet,” candidates’ strengths in areas like problem definition, creativity of solutions, and accuracy and clarity of coding are assessed whether the solution is right or wrong.

In the challenging assessment of the Full Stack Developer, with multiple skills, polyglot coding languages, and problems of end-to-end programming, Woven’s online coding challenge avoids the generic “pick your questions” assessment. At the same time, our test invites the job candidate in his or her career specialty to display knowledge, skill, and creativity expressed in coding.

The objectivity of our tests and the way they are scored help reduce bias in hiring. And the payoff is identification of coding talent in areas like software development, systems architecture, and debugging that can contribute to world-class teams.

Our professional staff is prepared to talk about your recruiting needs, your timeline, and your budget. Start your free trial today to discover the best assessment of talent in the roles you need on your software team.