KWAME OSEI OWUSU-GYIMAH
Java Spring Developer
PREVIOUSLY AT

Flexiple spent good amount of time understanding our requirements, resulting in accurate recommendations and quick ramp up by quality developers.
Overall Flexiple brought in high-level of transparency with quick turnarounds in the hiring process at a significantly lower cost than any alternate options.
Flexiple has been instrumental in helping us grow at a fast pace. Their vetting process for engineers is top notch and they connected us with quality talent quickly.
Flexiple Developers are reviewed on their experience and complexity of products built. Those who display depth and have worked on end-to-end projects are given an introductory call.
Over a call, the developer’s ability to communicate in an articulate manner is tested. A deeper understanding of the candidate’s technical experience and also motivation to freelance is achieved.
Over one or more F2F interviews, the developer’s involvement and performance in building complex software products are assessed. This sets the platform to delve deeper into technology-specific discussions.
Developers' mental agility and problem-solving abilities are tested through a coding test involving algorithmic as well as skill-specific problems. A mixture of live evaluation and timed coding tests is used.
The live experience of working with developers is verified by reaching out to past clients and/or employers. Inputs on various qualitative factors such as reliability, punctuality, communication and responsiveness are received.
Performance during each engagement is continually assessed. Our developers are expected to maintain Flexiple standards across all engagements with our customers.
The Spring Framework is an open-source application framework for developing Java applications. Java Enterprise Edition (Java EE) is one of the most popular frameworks, Spring helps developers create high performing applications using reusable and efficient code.
If you’re looking for a freelance Java Spring developer, this guide will come handy. We’ve included everything you need to know about the hiring process.
But before we get into the fundamentals of hiring a freelance Java Spring developer, let’s delve into some interesting facts about Java.
We have broken the sections into the following parts:
1. Let's introduce Spring Framework to you.
2. Why is Spring Framework widespread?
3. What are the tools used by Spring developers?
4. Writing the Job Description to hire a Java Spring developer
5. Interview Questions for hiring a Java Spring developer
- Basic Questions
- Advanced Questions
- Data Structures/Algo Questions
The following are some of the tools used by Spring developers at various stages of development:
1. IDE
An integrated development environment (IDE) is a software application that builds applications and combines common developer tools into a single GUI.
2. Plugins
Plugins are computer software that adds new functions to a host program without altering the host program itself.
Below are some key points that we at Flexiple have learned through trial and error - a process of filtering through over 15,000 developers.
Now that you have made a quality JD, it can still be tricky to evaluate the skills of your applicants. To help you with that, we have created a pool of questions that a good Java Spring developer should be comfortable with. You can check out some related interview questions on this page.
It is important to note that the ability to answer these questions doesn't imply that you have a top quality candidate. But it definitely is a big step in that direction.
To help you navigate through these questions, we’ve categorized the interview questions in 3 parts:
A. Basic concepts: Includes all basic concepts used across languages but we've focused on its significance in Java Spring Development. This section will give you an understanding of how strong their programming foundation is.
B. Advanced concepts: Includes all concepts that someone with higher expertise should know.
C. DS/Algorithm questions: To test the logical capability of the candidate.
An interface that contains only one abstract method is called a functional interface. Subsequently, functional interfaces can have only one functionality, however, they could contain multiple default methods.
With Java 8, lambda expressions can be used to instantiate functional interfaces making it much easier.
Examples of functional interfaces include - ActionListener, Comparable
Here is the code used to define a functional interface.
@FunctionalInterface interface Foo { void test(); }
public static int[] rotateBruteForce(int[] nums, int k) { for (int i = 0; i < k; i++) { for (int j = nums.length - 1; j > 0; j--) { // move each number by 1 place int temp = nums[j]; nums[j] = nums[j - 1]; nums[j - 1] = temp; } System.out.println("Array rotation after "+(i+1)+" step"); printArray(nums); System.out.println(); } return nums; }
Memoization is an approach that helps solve problems caused by dynamic programming. This process ensures that a given method does not execute more than once for the same inputs.
The return values are stored in Hashtables or Hashmaps and reused whenever required.
The code below is an example of memoization in a Fibonacci series.
import java.io.*; class GFG { // Fibonacci Series // using Recursion static int fib(int n) { // Base case if (n <= 1) return n; // recursive calls return fib(n - 1) + fib(n - 2); } // Driver Code public static void main (String[] args) { int n = 6; System.out.println(fib(n)); } }
class ValidParenthesesFunc { func isValid(_ s: String) -> Bool { var stc = [Character]() for char in s { if char == "(" || char == "[" || char == "{" { stc.append(char) } else if char == ")" { guard stc.count != 0 && stc.removeLast() == "(" else { return false } } else if char == "]" { guard stc.count != 0 && stc.removeLast() == "[" else { return false } } else if char == "}" { guard stc.count != 0 && stc.removeLast() == "{" else { return false } } } return stc.isEmpty } }
The above code will input 0(false).
import java.util.Scanner; public class Palindrome { public static void main (String[] args) { String original, reverse = ""; Scanner in = new Scanner(System.in); int length; System.out.println("Enter a number or a string"); original = in.nextLine(); length = original.length(); for (int i =length -1; i>;=0; i--) { reverse = reverse + original.charAt(i); } System.out.println("The reverse is: " +reverse); if(original.equals(reverse)) System.out.println("The string is a palindrome"); else System.out.println("The stringis not a palindrome"); } }
Output: For String- Enter a number or a string sam The reverse is: mas The string is not a palindrome For Number-Enter a number or a string 99 The reverse is: 99 The number is a palindrome
class Test { public static void main(String args[]) { String str1 = new String("Hello World"); String str2 = new String("Hello World"); String str3 = "Hello World"; String str4 = "Hello World"; int a = 0, b = 0, c = 0; if (str3 == str4) a = 1; else a = 2; if (str1.equals(str3)) b = 1; else b = 2; if (str1 == str4) c = 1; else c = 2; System.out.println("a= " + a + " b= " + b + " c= " + c); } }
D. a=1 b=1 c=2 because a new memory is created when we make an object with the help of the ‘new’ keyword, and the reference variable contains the memory location. Here the memory is created with the same string twice, but since we are comparing objects and not strings, the object will point to a different memory location and so they are not equal.