Improved code using transient to provide caching of API calls.

gistfile1.txt

<?php
/**
 * This code retrieves course data from an external API and displays it in the user's
 * My Account area. A merchant has noticed that there's a delay when loading the page.
 * 
 * 1) What changes would you suggest to reduce or remove that delay?
 * 2) Is there any other code changes that you would make?
 */
public function add_my_courses_section() {
	$courses     = null;
	$sso_link    = null;
	$api_user_id = get_user_meta( get_current_user_id(), '_external_api_user_id', true );

	if ( ! $api_user_id ) {
		return;
	}
	
	if ( false === ( $courses = get_transient( '_external_api_courses_' . $api_user_id ) ) ) {
     		$courses  = $this->get_api()->get_courses_assigned_to_user( $api_user_id );
		$sso_link = $this->get_api()->get_sso_link( $api_user_id );
		set_transient( '_external_api_courses_' . $api_user_id, $courses, DAY_IN_SECONDS );
		set_transient( '_external_api_sso_link_' . $api_user_id, $sso_link, DAY_IN_SECONDS );
	} else {
		$sso_link = get_transient( '_external_api_sso_link_' . $api_user_id );
	}

	?>
	<h2 style="margin-top: 40px;"><?php echo __( 'My Courses', 'text-domain' ); ?></h2>
	<table>
		<thead><tr>
			<th><?php echo __( 'Course Code', 'text-domain' ); ?></th>
			<th><?php echo __( 'Course Title', 'text-domain' ); ?></th>
			<th><?php echo __( 'Completion', 'text-domain' ); ?></th>
			<th><?php echo __( 'Date Completed', 'text-domain' ); ?></th>
		</tr></thead>
		<tbody>
		<?php
		foreach( $courses as $course ) :
			?><tr>
			<td><?php echo __( $course['Code'] ); ?></td>
			<td><?php echo __( $course['Name'] ); ?></td>
			<td><?php echo __( $course['PercentageComplete'] ); ?> &#37;</td>
			<td><?php echo __( $course['DateCompleted'] ); ?></td>
			</tr>
		<?php endforeach;
		?>
		</tbody>
	</table>
	<p><a href="<?php echo $sso_link ?>" target="_blank" class="button <?php echo $_GET['active_course']; ?>"><?php echo __( 'Course Login', 'text-domain' ); ?></a></p>

	<?php
}