Coding tasks to assign to PHP developer candidates

When interviewing candidates for a PHP developer position, you don’t have the luxury of wasting time and money or discussing theory only. You must use correct, suitable, and relevant coding tasks that test a candidate’s ability to code and work with PHP.

Abdelaziz Mirad, a fullstack developer at Proxify, helped us narrow down the most concise and relevant coding tasks to assign when interviewing candidates for the PHP developer role.

The five coding assignment suggestions

Let’s look at the five coding tasks with their corresponding expected answers.

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1.Payment processor

This task is essential to show how to properly implement and use a basic payment processor only through the payments functionality (it returns true as a boolean value). This task is vital for following the OOP design best practices (object-oriented programming). One segment of the task is, for example, the PayPal and Wallet (used for cryptocurrencies) payment methods, and the assumptions here are:

  • The action of the payment method is to display its name in a string.

  • Wallet and PayPal methods are defined with the wallet address and the email address as function parameters respectively.

  • Regarding the payment usage demo, after implementing the steps above, a candidate should show us how they do all of this (the above methods such as PayPal and Wallet)

  • Relevance of the task and example points:

  • Use the Strategy Design Pattern – This should be done by defining the Payment methods separately and implementing the same strategy interface.

  • Loose coupling – A candidate should introduce a new payment Method without modifying the existing payment methods or their context.

  • Applying the Single-responsibility principle – For each payment method, those methods are responsible only for a specific way of payment, such as the one with PayPal (in this case, only PayPal transactions are applicable).

  • Applying Open/Closed principle – PaymentService as a context class is now open for extension with new methods but closed for modifying it. This is because there is no need for an update when introducing new payment methods.

  • Dependency Injection – With this, we should see how a Dependency Injection works and how precisely and smoothly the payment methods are injected into the payment service.

An example of a code for this task:

<?php

// Define the Strategy class
interface PaymentInterface{
   /* Declare the main payments algorithms */
   public function pay(int $amount): bool;
}

// Define Paypal class
public class PayPal implements PaymentInterface{

   private string $email;

   public function __constuct(string $email){
       $this->email = $email;
   }

   /**
    * Get the value of email
    */
   public function getEmail(): string
   {
       return $this->email;
   }

   public function pay(int $amount): bool
   {
       echo "PayPal payment ".$amount." processing from:". $this->getEmail();

       return true;
   }
}

// Define Wallet class
public class Wallet implements PaymentInterface{

   private string $walletAddress;

   public function __constuct(string $walletAddress){
       $this->paymentProcessor = $paymentProcessor;
   }

   /**
    * Get the value of walletAddress
    */
   public function getWalletAddress(): string
   {
       return $this->walletAddress;
   }

   public function pay(int $amount): bool
   {
       echo "Wallet payment ".$amount." processing from: " . $this->getWalletAddress();

       return true;
   }
}

// Define our context Payment Service
public class PaymentService{

   private PaymentInterface $paymentProcessor;

   public function makePayment(int $amount): bool
   {
       return $this->paymentProcessor()->pay($amount);
   }

   public function setPaymentProcessor($paymentProcessor): void
   {
       $this->paymentProcessor = $paymentProcessor;
   }
}

// Demo
// Client can easily pick/interchange the Payment method at the run time
$payment = new PaymentService();
// Process using Crypto Wallet
$payment->setPaymentProcessor(new Wallet("1C1zS5eP8QFzfi2DMPTfTL5SLmv7DivdNb"));
$payment->makePayment($amount);
// Process using Paypal
$payment->setPaymentProcessor(new PayPal("[email protected]"));
$payment->makePayment($amount);

2.Unit testing

A candidate here should add unit tests to a child entity to test each method in the class and confirm that it works exactly as intended.

For example, the code below shows a definition of a child entity to create unit tests for.

<?php

declare(strict_types=1);

namespace TestProject;

use InvalidArgumentException;

class Kid
{
   public int $age;
   public string $name;
   public array $hobbies = [];

   public function __construct(int $age, string $name)
   {
       $this->age = $age;
       $this->name = $name;
   }

   public function getName(): string
   {
       return $this->name;
   }

   public function getAge(): int
   {
       return $this->age;
   }

   public function addHobby(string $hobby): void
   {
       $this->hobbies[] = $hobby;
   }

   public function removeHobby(string $hobby): void
   {
       if (!in_array($hobby, $this->hobbies)) {
           throw new InvalidArgumentException("No such hobby: " . $hobby);
       }
       unset($this->hobbies[array_search($hobby, $this->hobbies)]);
   }
}
  • Relevance of the task and example points:

Unit testing: Here, you should confirm that the candidate has a solid understanding of the unit test software process, which is highly recommended for all complex and large-scale projects to ensure smooth running of every command/action.

An example of a code for this task:

<?php

declare(strict_types=1);

namespace TestProject;

use PHPUnit\Framework\TestCase;

final class KidTest extends TestCase
{
   // 1. Test Constructor
   public function testConstructor()
   {
       $kid = new Kid(6, 'Abdo');

       $this->assertSame('Abdo', $kid->name);
       $this->assertSame(6, $kid->age);
       $this->assertEmpty($kid->hobbies);
   }

   // 2. Test testName
   public function testGetName()
   {
       $kid = new Kid(6, 'Abdo');

       $this->assertIsString($kid->getName());
       $this->assertEquals('Abdo', $kid->getName());
   }

   // 3. Test getAge
   public function testGetAge()
   {
       $kid = new Kid(6, 'Abdo');

       $this->assertIsString($kid->getAge());
       $this->assertEquals('6', $kid->getAge());
   }

   // 4. Test addHobbies
   public function testAddHobby()
   {
       $kid = new Kid(6, 'Abdo');

       $kid->addHobby('Football');

       $this->assertContains('Football', $kid->hobbies);
       $this->assertCount(1, $kid->hobbies);
   }

   // 5. Test removeHobby
   public function testRemoveHobby()
   {
       $kid = new Kid(6, 'Abdo');

       $this->assertTrue($kid->addHobby('Football'));
       $this->assertTrue($kid->addHobby('Video Games'));

       $kid->removeHobby('Football');

       $this->assertNotContains('Football', $kid->hobbies);
       $this->assertCount(1, $kid->hobbies);
   }
}

3.CRUD operations

A candidate should receive a task for creating two important entities: Employee and Customer. These entities should implement primary CRUD operations. With this, the entities would look the same for now but they will be ready for extension and for adding specific operations to each entity later on depending on the specific requirements.

  • Relevance of the task and example points:

  • Data validation and sanitization – The candidate should validate and sanitize the user input before interacting with the database. This is done to prevent any vulnerabilities in security, such as SQL injection attacks. Use parameterized queries or prepared statements to pass the user input to the database safely.

  • Dependency injection – This shows clearly how the dependency injection works and how it is smoothly injected into the DB connection methods to construct DatabaseObject.

  • Inheritance principle – This is one of the most important principles in OOP because it provides reusability of existing code and helps avoid duplicate code. We can see this clearly in the Employee and Customer entities where we avoided rewriting and duplicating all the inherited methods.

  • Separation of concerns – Here, DatabaseTrait is used to implement only the low level operations database, most methods commonly used for storing data. This shows how dividing tasks into modular units and utilising all units without mixing them.

An example of a code for this task:

  • For Employee.php
<?
declare(strict_types=1);

class Employee extends UserObject {
   protected static string $tableName="employee";
}
  • For Customer.php
<?
declare(strict_types=1);

class Customer extends UserObject {
   protected static string $tableName="customer";
}
  • For DatabaseTrait.php
<?
declare(strict_types=1);

trait DatabaseTrait{
   protected static string $tableName="";
   protected static $dbFields = array('id', 'name', 'email');
   protected function sanitizedAttributes(): array{
       $cleanAttributes = array();
       foreach($this->attributes() as $key => $value){
         $cleanAttributes[$key] = $this->escapeValue($value);
       }
       return $cleanAttributes;
   }
   protected function query(string $sql){
       $result = mysqli_query($this->connection, $sql);
       $this->confirmQuery($result);

       return $result;
   }
   protected function confirmQuery($result){
       if (!$result) {
           $output = "Database failure: " . mysqli_error($this->connection);
           die( $output );
       }
   }
   protected function fetchArray($resultSet): ?array{
       return mysqli_fetch_array($resultSet);
   }
   protected function instantiate(array $record): self{
       $object = new self($this->connection);

       foreach($record as $attribute=>$value){
           if($object->hasAttribute($attribute)) {
               $object->$attribute = $value;
           }
       }

       return $object;
   }
   private function insertId(){
       return mysqli_insert_id($this->connection);
   }
   private function escapeValue( $value ){
       $value = mysqli_real_escape_string( $this->connection, $value );
       return $value;
   }
   private function affectedRows(){
       return mysqli_affected_rows($this->connection);
   }
   private function hasAttribute($attribute){
       return array_key_exists($attribute, $this->attributes());
   }
   private function attributes(){
     $attributes = array();
     foreach($this->dbFields as $field) {
       if(property_exists($this, $field)) {
           $attributes[$field] = $this->$field;
       }
     }
     return $attributes;
   }
}
  • For UserObject.php
<?
declare(strict_types=1);

abstract class UserObject{
   use DatabaseTrait;
   protected static string $tableName="";
   protected static $dbFields = array('id', 'name', 'email');

   private int $id;
   private string $name;
   private string $email;
   private $connection;

   function __construct($connection) {
       $this->connection = $connection;
   }
   public function getId(){
       return $this->id;
   }
   public function getName(){
       return $this->name;
   }
   public function setName($name){
       $this->name = $name;

       return $this;
   }
   public function getEmail(){
       return $this->email;
   }
   public function setEmail($email){
       $this->email = $email;
       return $this;
   } 
   public static function findBySql(string $sql = ""): array{
       $resultSet = self::query($sql);
       $object_array = array();
       while ($row = self::fetchArray($resultSet)) {
           $object_array[] = self::instantiate($row);
       }
       return $object_array;
   }
   public static function findAll(): array{
       return self::findBySql("SELECT * FROM ".self::$tableName);
   }
   public static function findById(int $id=0){
       $resultArray = self::findBySql("SELECT * FROM ".self::$tableName." WHERE id={$id} LIMIT 1");
       return !empty($resultArray) ? array_shift($resultArray) : null;
   }
   public function save(): bool{
     return isset($this->id) ? $this->update() : $this->create();
   }
   public function create(): bool{
       $attributes = $this->sanitizedAttributes();
       array_shift($attributes);
       $sql = "INSERT INTO ".self::$tableName." (";
       $sql .= join(", ", array_keys($attributes));
       $sql .= ") VALUES ('";
       $sql .= join("', '", array_values($attributes));
       $sql .= "')";
       if($this->query($sql)) {
           $this->id = self::insertId();
           return true;
       } else {
           return false;
       }
   }
   public function update(): bool{
       $attributes = $this->sanitizedAttributes();
       $attribute_pairs = array();
       foreach($attributes as $key => $value) {
           $attribute_pairs[] = "{$key}='{$value}'";
       }
       $sql = "UPDATE ".self::$tableName." SET ";
       $sql .= join(", ", $attribute_pairs);
       $sql .= " WHERE id=". self::escapeValue($this->id);
       $this->query($sql);
       return (self::affectedRows() == 1) ? true : false;
   }
   public function delete(): bool{
     $sql = "DELETE FROM ".self::$tableName;
     $sql .= " WHERE id=". self::escapeValue($this->id);
     $sql .= " LIMIT 1";
     $this->query($sql);
     return (self::affectedRows() == 1) ? true : false;
   }
}

4.Authentication system

Here, the candidate should create a simple authentication (registration and login) system with PHP and MySQL (this is very common in modern web applications, forcing the user to prove their identity before being given access to any information system. The user should implement login, registration, and logout functionalities only).

  • Relevance of the task and example points:

  • Data validation and sanitization – The user input should be validated and sanitized before interacting with the database to prevent security vulnerabilities. It is advisable to use parameterized queries and prepared statements.

  • Request handling process – This shows how the requests are meant to be handled depending on the different methods used.

  • Security and SQL injection – This is for validating the data before inserting it directly into the database. Again, done to avoid SQL injections.

  • Error handling – A candidate should implement a suitable mechanism by catching all possible errors during the app execution.

An example of a code for this task:

  • For Config.php
<?php
define('DB_SERVER', 'localhost');
define('DB_USERNAME', 'root');
define('DB_NAME', 'my_db');
define('DB_PASSWORD', '');

$link = mysqli_connect(DB_SERVER, DB_USERNAME, DB_PASSWORD, DB_NAME);
if($link === false){
   die("ERROR: Could not connect. " . mysqli_connect_error());
}
?>
  • For Index.php
<?php
session_start();
if(!isset($_SESSION["is_login"]) || $_SESSION["is_login"] !== true){
   header("location: login.php");
   exit;
}
?>
  • For Login.php
<?php
session_start();

if(isset($_SESSION["is_login"]) && $_SESSION["is_login"] === true){
   header("location: index.php");
   exit;
}

require_once "config.php";
$username = $password = "";
$username_error = $password_error = $login_error = "";

if($_SERVER["REQUEST_METHOD"] == "POST"){
   if(empty(trim($_POST["username"]))){
       $username_error = "Please enter username.";
   } else{
       $username = trim($_POST["username"]);
   }

   if(empty(trim($_POST["password"]))){
       $password_error = "Please enter your password.";
   } else{
       $password = trim($_POST["password"]);
   }

   if(empty($username_error) && empty($password_error)){
       $sql = "SELECT id, username, password FROM users WHERE username = ?";

       if($stmt = mysqli_prepare($link, $sql)){
           mysqli_stmt_bind_param($stmt, "s", $param_username);

           $param_username = $username;

           if(mysqli_stmt_execute($stmt)){
               mysqli_stmt_store_result($stmt);

               if(mysqli_stmt_num_rows($stmt) == 1){                   
                   mysqli_stmt_bind_result($stmt, $id, $username, $hashed_password);
                   if(mysqli_stmt_fetch($stmt)){
                       if(password_verify($password, $hashed_password)){
                           session_start();

                           $_SESSION["is_login"] = true;
                           $_SESSION["id"] = $id;
                           $_SESSION["username"] = $username;                           

                           header("location: index.php");
                       } else{
                           $login_error = "Invalid username or password.";
                       }
                   }
               } else{
                   $login_error = "Invalid username or password.";
               }
           } else{
               echo "Oops! Something went wrong. Please try again later.";
           }
           mysqli_stmt_close($stmt);
       }
   }
   mysqli_close($link);
}
?>
<html>
<head>
   <meta charset="UTF-8">
   <title>Login</title>
</head>
<body>
   <div>
       <h2>Login</h2>
       <p>Please enter Username/Password.</p>

       <?php
       if(!empty($login_error)){
           echo '<div>' . $login_error . '</div>';
       }       
       ?>

       <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
           <div>
               <label>Username</label>
               <input type="text" name="username" value="<?php echo $username; ?>">
               <span ><?php echo $username_error; ?></span>
           </div>   
           <div>
               <label>Password</label>
               <input type="password" name="password">
               <span><?php echo $password_error; ?></span>
           </div>
           <div>
               <input type="submit" value="Login">
           </div>
           <p>Register here <a href="register.php">Register</a>.</p>
       </form>
   </div>
</body>
</html>
  • For Logout.php
<?php
session_start();
$_SESSION = array();
session_destroy();
header("location: login.php");
exit;
?>
  • For Register.php
<?php
require_once "config.php";

$username = $password = $confirm_password = "";
$username_error = $password_error = $confirm_password_error = "";
if($_SERVER["REQUEST_METHOD"] == "POST"){
   if(empty(trim($_POST["username"]))){
       $username_error = "Please enter a username.";
   } elseif(!preg_match('/^[a-zA-Z0-9_]+$/', trim($_POST["username"]))){
       $username_error = "Username can only contain letters, numbers, and underscores.";
   } else{
       $sql = "SELECT id FROM users WHERE username = ?";

       if($statement = mysqli_prepare($link, $sql)){
           mysqli_stmt_bind_param($statement, "s", $param_username);

           $param_username = trim($_POST["username"]);
           if(mysqli_stmt_execute($statement)){
               mysqli_stmt_store_result($statement);

               if(mysqli_stmt_num_rows($statement) == 1){
                   $username_error = "This username is already taken.";
               } else{
                   $username = trim($_POST["username"]);
               }
           } else{
               echo "Server busy! Please try later.";
           }

           mysqli_stmt_close($statement);
       }
   }

   if(empty(trim($_POST["password"]))){
       $password_error = "Please enter a password.";    
   } elseif(strlen(trim($_POST["password"])) < 8){
       $password_error = "Password must have atleast 8 characters.";
   } else{
       $password = trim($_POST["password"]);
   }

   if(empty(trim($_POST["confirm_password"]))){
       $confirm_password_error = "Please confirm password.";    
   } else{
       $confirm_password = trim($_POST["confirm_password"]);
       if(empty($password_error) && ($password != $confirm_password)){
           $confirm_password_error = "Password did not match.";
       }
   }

   if(empty($username_error) && empty($password_error) && empty($confirm_password_error)){

       $sql = "INSERT INTO users (username, password) VALUES (?, ?)";

       if($statement = mysqli_prepare($link, $sql)){
           mysqli_stmt_bind_param($statement, "ss", $param_username, $param_password);

           $param_username = $username;
           $param_password = password_hash($password, PASSWORD_DEFAULT);
           if(mysqli_stmt_execute($statement)){
               header("location: login.php");
           } else{
               echo "Oops! Something went wrong. Please try again later.";
           }
           mysqli_stmt_close($statement);
       }
   }
   mysqli_close($link);
}
?>
<html>
<head>
   <meta charset="UTF-8">
   <title>Register</title>
</head>
<body>
   <div>
       <h2>Register</h2>
       <p>Please fill this form to create an account.</p>
       <form action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="post">
           <div>
               <label>Username</label>
               <input type="text" name="username" value="<?php echo $username; ?>">
               <span><?php echo $username_error; ?></span>
           </div>   
           <div>
               <label>Password</label>
               <input type="password" name="password" value="<?php echo $password; ?>">
               <span><?php echo $password_error; ?></span>
           </div>
           <div>
               <label>Confirm Password</label>
               <input type="password" name="confirm_password" value="<?php echo $confirm_password; ?>">
               <span><?php echo $confirm_password_error; ?></span>
           </div>
           <div>
               <input type="submit"value="Submit">
               <input type="reset" value="Reset">
           </div>
           <p>Already have an account? <a href="login.php">Login</a>.</p>
       </form>
   </div>   
</body>
</html>

5.Custom file processing class

For this task, the candidate should implement a file processing module based on the native PHP file functions to handle possible errors before they happen. By defining the custom exceptions indicating an error type, the primary methods that work with files need to be implemented (this includes reading and writing at once, reading/writing line by line, and saving/destroying a file. We can assume writing/dealing with strings only for simplicity here.

  • Relevance of the task and example points:

  • Usage of inheritance principle – Providing existing code reusability and avoiding code duplication.

  • Error handling – The candidate should implement proper error handling mechanisms during file processing. They should use try-catch blocks to catch and handle exceptions (file access errors, format errors, and other issues that might come up). If needed, they should provide meaningful error messages, where needed, to help the users understand and resolve these errors.

An example of a code for this task:

<?
final class InvalidFilenameException extends \Exception {
   function __construct( $filename ){
       $this->message = 'Invalid filename: "' . $filename . '"';
   }
}
final class InvalidModeException extends \Exception {
   function __construct( $mode ){
       $this->message = 'Invalid mode: "' . $mode . '"';
   }
}
final class WriteException extends \Exception {
   function __construct( $filename ){
       $this->message = 'Could not write into "' . $filename . '"';
   }
}
final class ReadException extends \Exception {
   function __construct( $filename ){
       $this->message = 'Could not read "' . $filename . '"';
   }
}
final class EOF extends \Exception {
   function __construct( $filename ){
       $this->message = 'End Of File "' . $filename . '"';
   }
}

final class FileProcessing {

   const READ = 1;
   const WRITE = 2;
   const BINARY = 4;
   const EMPTY = "";

   const EOL = PHP_EOL;

   private $info=array(
       'content'=>'',
       'path'=>'',
       'name'=>'',
       'length'=>0,
       'position'=>0,
       'mode'=>1
   );

   function __construct( string $filename, int $mode = 1 ){

       $this->info['mode'] = $mode & 7;
       if( !$this->info['mode'] )
       {
           throw new InvalidModeException( $mode );
       }

       if( $filename == self::EMPTY )
       {
           throw new InvalidFilenameException( $filename );
       }

       $this->info['path'] = dirname( $filename );
       if( !$this->info['path'] )
       {
           $this->info['path'] = getcwd();
       }

       $this->info['name'] = basename( $filename );
       if( !$this->info['path'] )
       {
           throw new InvalidFilenameException( $filename );
       }

       if( $mode & self::READ )
       {
           $this->info['content'] = file_get_contents( $filename );

           if( $this->info['content'] === false)
           {
               throw new ReadException( $filename );
           }

           $this->info['length'] = strlen( $this->info['content'] );
       }
   }

   function eof(): bool
   {
       return $this->info['position'] >= $this->info['length'];
   }

   function read( $bytes = -1 ): string
   {
       if( !( $this->info['mode'] & self::READ ) )
       {
           throw new ReadException( $this->info['name'] );
       }

       if( $this->eof() )
       {
           throw new EOF( $this->info['name'] );
       }

       if( $bytes < 0 || $bytes > $this->info['length'] - $this->info['position'] )
       {
           $bytes = $this->info['length'] - $this->info['position'];
       }

       $p = $this->info['position'];
       $this->info['position'] += $bytes;

       return '' . substr( $this->info['content'], $p, $bytes );
   }
   function readln( $trim = true ): string
   {
       if( !( $this->info['mode'] & self::READ ) )
       {
           throw new ReadException( $this->info['name'] );
       }

       if( $this->eof() )
       {
           throw new EOF( $this->info['name'] );
       }

       $lineEnd = strpos( $this->info['content'], self::EOL, $this->info['position'] );
       $p = $this->info['position'];

       if( $lineEnd === false )
       {
           $this->info['position'] = $this->info['length'];
           return '' . substr( $this->info['content'], $p );
       }
       else
       {
           $this->info['position'] = $lineEnd + strlen( self::EOL );
           return '' . substr( $this->info['content'], $p, $trim ? $lineEnd : $this->info['position'] );
       }
   }

   function write( $data ): self
   {
       if( !( $this->info['mode'] & self::WRITE ) )
       {
           throw new WriteException( $this->info['name'] );
       }

       list($begin,$end) = array( substr( $this->info['content'],0, $this->info['position'] ), substr( $this->info['content'], $this->info['position'] ) );

       $this->info['position'] = strlen( $begin . $data );

       $this->info['content'] = $begin . $data . $end;

       $this->info['length'] = strlen( $this->info['content'] );

       return $this;
   }
   function writeln( $data ): self
   {
       return $this->write( $data . self::EOL );
   }

   function seek( int $byte )
   {
       if( is_numeric( $byte ) )
       {
           if( $byte >= $this->info['length'] )
           {
               $this->info['position'] = $this->info['length'];
           }
           else if( $byte >= 0)
           {
               $this->info['position'] = (int)$byte;
           }
           else
           {
               $this->info['position'] = $this->info['length'] - 1;
           }
       }

       return $this;
   }
   function start()
   {
       return $this->seek( 0 );
   }
   function end()
   {
       return $this->seek( -1 );
   }

   function pos()
   {
       return $this->info['position'];
   }

   function size()
   {
       return $this->info['length'];
   }

   function save()
   {
       return file_put_contents( $this->info['path'] . DIRECTORY_SEPARATOR . $this->info['name'], $this->info['content'] );
   }

   function destroy(): void
   {
       $this->info = array(
           'content'=>'',
           'path'=>'',
           'name'=>'',
           'length'=>0,
           'position'=>0,
           'mode'=>1
       );
   }
}

$file = new FileProcessing("test.txt");
$firstLineContent = $file->writeln("First Line")->start()->writeln("Re-write Line")->start()->readln(true);

//Should output Second Line
echo $firstLineContent;

Benefits and importance of using coding assignments

Practical testing of PHP developers' skills saves you time on lengthy processes around recruitment and hiring. Most importantly, when you assign coding tasks, you are one step closer to resolving a real-world problem by assigning PHP developer candidates a real-world scenario. Completely free of bias, you will efficiently see who’s a good match in no time.

Coding tasks reveal much more than technical knowledge – they also tell you how well they handle working with some deadlines and certain (healthy) pressure. You will see how well they use critical thinking with hands-on experience.

Independent working skills are another crucial factor. If a candidate handles all coding tasks well independently, without asking for assistance or group work, they can also take on challenges autonomously in the future.

The core quality of a PHP developer is first seen in their clean code, delivery of functional solutions, and solid knowledge of accompanying elements of this framework.

Another essential benefit is easier documentation and tracking of all applicants for the PHP developer role. All tests' results must be safely organized and documented for easier grading and comparison and for accessible reference.

What makes an excellent coding assessment experience?

Here are some valuable tips for those organising and overseeing the interviewing.

Be as straightforward as possible with the instructions

To avoid getting answers to the wrong questions, set clear explanations for the tasks and the other rules covered in the testing, such as deliverables, time, constraints, and similar.

Make the scope realistic

If the overall scope is manageable, interviewing and evaluating will be easy. The tasks you assign have to be relevant to the role, with expected answers documented aside before the testing, and with a planned out time frame too. If the task is complex, it would require more time allocated to finish, and vice versa. And adjust the complexity of questions according to the experience level – senior developers are expected to know more than medior or junior ones, and so on.

Are you just one person responsible for evaluating, or do you have a large team helping you? Can you handle the whole scope of candidates alone? Think of everything in realistic terms and expectations.

Refer to real-world examples

There is no great point in assigning tasks that don’t refer to something real-world, practical, or valuable. The tasks you give should be relevant to the challenges your company faces in the long run regarding web development.

Have standardized criteria

Candidates could get demotivated if they notice bias or have double standards for tests and evaluations. The rules must be equal for everyone, and the task complexity must be the same for everyone interviewing for the PHP developer position.

Be flexible

If there is aslight delay in the deliverables due to severe or unexpected, valid reasons, you should keep these in mind.

But also, the other spectrum of flexibility means you allow candidates to choose what hours they could take the test, as long as you provide them with a calendar deadline for submissions.

Allocate enough time

You best know the complexity of tasks. If they are complex, be realistic about the time you give because if there is not enough time, you risk stressing out the PHP developers and getting some flawed deliverables, done in a rush.

Provide resources/tools

If needed, and if that’s your usual practice, refer candidates to any valuable guidelines and resources they need to know or look at before the assessment.

Make the environment welcoming and professional

Even though the testing is an efficient and concise way of interviewing, it is advisable to adopt an approachable attitude that encourages all candidates to give it a shot and give their best.

Provide feedback

Lastly, don’t forget to offer feedback, regardless of your final decision. Hired or not, if a dev candidate took some time to prepare and do the tests, they deserve to know your final decision after a while. By doing this, you represent the company's brand as responsible, respectful, and professional.

Benefits of hiring a vetted PHP developer

In the long run, your business and company will succeed tremendously in almost any work engagement if you hire good PHP developers. And to do so, you must ensure you’ve used accurate, relevant coding tasks. PHP is widespread, versatile, and flexible for usage, so it’s a most welcome addition to developers’ resources.

Many websites are based on PHP, popularly year by year, and the number of developers using the PHP frameworks is just as impressive.

What’s in it for you and the business dynamic?

  • Less development time – Since PHP is relatively simple to learn and use, the developers will spend less time on the usual development processes.

  • Saving on costs – Needing less time to use PHP in development means saving time and money in the long run.

  • Open source accessibility – Speaking of saving on costs, PHP is also open source and free for anyone to use. Open source also means that your developers will always have access to PHP frameworks (such as Symfony and Laravel) and any valuable information and novelties.

  • Multi-applicable – The versatility of PHP allows for usage on macOS, Linux, and Windows; for most web browsers and servers, there is adequate support too.

  • No obstacles – Over the years, PHP was thoroughly debugged where needed, “smoothened out,” upgraded, and made more stable and secure for developers to use. It is now highly efficient, safe, and stable.

  • Easy database connections – With PHP, it is easy to link to needed databases, and developers can choose what works best.

  • Safety and speed – Using PHP means developers make ultra-fast and secure websites, which is always the ultimate goal. With newer versions of PHP, the development speed is skyrocketing. For any possible issues or vulnerabilities with PHP, community support offers helpful practices for preventing problems and cyber issues.

  • Helpful tools and practices – Developers can freely refer to the broader community of PHP developers for adequate support when needed through FAQs, tutorials, and similar.

Marija Neshkoska

Marija Neshkoska

Content Writer

Abdelaziz Mirad

Abdelaziz Mirad

Fullstack developer

Extensive experience with PHP

Find your next developer within days, not months

In a short 25-minute call, we would like to:

  • Understand your development needs
  • Explain our process to match you with qualified, vetted developers from our network
  • You are presented the right candidates 2 days in average after we talk

Not sure where to start? Let’s have a chat