We’re Hiring! Front End Lead Based in Stockholm

We are looking for a front end expert to take on the role of lead front end developer for the loadimpact.com site and application, being a part of our upcoming redesign of the whole site, service and user flow.

What is loadimpact.com then?

Load Impact is the world’s most widely used online load testing service, with over 100,000 users from 190+ countries and over a million executed load tests – Google “web load test”!

The company is small but very experienced in developing applications for performance testing and monitoring. We started out as a software development consulting company way back in 2000, developing performance test and measurement software for customers such as Nasdaq and the European space agency. We wrote both hardcore, low-level networking software and high-level web user interfaces and became quite good at both of those things. We pride ourselves on understanding the lower levels of a networked application while at the same time realizing how incredibly important UX is. In 2009 we took the step and launched loadimpact.com, becoming a product company rather than a consulting company, and we have never looked back.

We are located in Stockholm, Sweden and San Francisco, USA. This job opening is in Stockholm.

This is a chance to get the best of both worlds – you get to build something practically from scratch and decide how to do things while at the same time you’re supported by a successful, global business with a very strong user base and sound financial backing. You will be part of a small and very competent dev team, using the latest and greatest technologies and working in a modern and agile environment.

Being part of a small team means you get a lot of say in what happens in general, and can influence your own work situation. As a company, we are very “flat” (no hierarchies) and that means you’ll have a say in most decisions we make as a company, if you want to.

You need to be really, really good at:

HTML, CSS & Javascript

You need to be be knowledgeable about:

Usability / UI design
Common JS libraries/frameworks
Browser support/portability/quirks
Common data formats: JSON, XML
Responsive design

You should have some knowledge or experience of:

Client-side optimization (minification, sprites, lazy-loading etc)
Git / Github
SEO basics (the common-sense stuff, no black hat tricks thank you)
Common web servers: Apache, Nginx
Web analytics & growth hacking
SQL
Cloud operations (e.g. using Amazon EC2 and/or other AWS services)
Web application protocols: HTTP, HTTPS

The office is located in Stockholm, Sweden. A very scenic city, with excellent infrastructure, clean streets, low crime, many bars, fantastic coffee. A bit cool in winter, but who cares, we just buy more coffee. There is also a very vibrant tech startup scene in Stockholm, much thanks to companies like Spotify, Skype, King.com (Candy crush), Mojang (Minecraft) and others that started and are still operating here. The city is attracting more and more world-class IT entrepreneurs and developers – it is a very dynamic environment to work in, with a lot of industry colleagues to hang out with and learn from. Our office is very centrally located, by the way, with a fantastic view of the city harbour 🙂

 

Actual view from our desks!

How to apply:

Email your resume and info to ragnar@loadimpact.com.

We look froward to hearing from you!

Deadline July 1, 2014.

Automating Load Testing to Improve Web Application Performance

This blog post was originally written for the Rackspace DevOps blog. Check out this post and more great dev advice on their blog.

…….

Web application performance is a moving target. During design and implementation, a lot of big and small decisions are made that affect application performance – for good and bad. You’ve heard it before. But since performance can be ruined many times throughout a project, good application performance simply can not be added as an extra feature at the end of a project.

The modern solution to mitigate quality problems throughout the application development life cycle is called Continuous Integration, or just CI. The benefits of using CI are many, but for me, the most important factor for embracing CI is the ability to run automated tests frequently and to trace application performance, since such tests need to be added to the stack of automated tests already being generated. If you have load tests carried out throughout your project development, you can proactively trace how performance is affected.

The key is being able to automate load testing. But how do we do that? Naturally, it depends on your environment. Assuming that you’re building a web application and that your build environment is already in the cloud, it would be ideal to start using a cloud based load testing service such as Load Impact to automatically generate load and measure performance. In fact, libcurl will get you almost all the way.

Load Impact’s Continuous Delivery API was created to enable developers to run load tests programmatically. It’s an http based REST API that uses JSON for passing parameters. In its most basic form, you can run the following from a command line:

$ curl -X POST https://api.loadimpact.com/v2/test-configs/X/start -u token: {"id":Y}
$ curl -X GET https://api.loadimpact.com/v2/tests/Y/results -u token: > out.json

In this example X = the LoadImpact test config id, Y = the test result id and token = your LoadImpact API token. Please note that token is sent as an http username but with a blank password.

Since JSON is not that easy to work with from the command line, using PHP or Perl to wrap the calls in a script makes sense. A more complete sample doesn’t really fit into this blog post, but at a pseudo level you want to:

<?php

$token = '123456789';
$urlbase = 'https://api.loadimpact.com/v2/';
$config_id = 999;

// Start test and get id from JSON return
$test = http_post($urlbase . "/test-configs/$config_id/start"));

$done = FALSE;
while(!$done) {
  sleep(30);
  $status = http_get($urlbase . "/tests/{$test->id}");
  $if($status->status > 2) $done = TRUE;
}

$result = http_get($urlbase . "/tests{$test-id}/results");
$last = count($results->__li_user_load_time); 
echo $results->__li_user_load_time[$last]->value; ?>

First, some variables are set, the existing test configuration id and my API token being the most interesting.

Second, I ask Load Impact to launch the test configuration and store the test id. Wait for the test to finish by asking for its status code every 30 seconds.

Lastly, when I know the test if finished, I ask for the test result that I can then query for values. In this example, I simply echo the last measurement of the actual load time. If needed, the Load Impact API also allows me to manipulate the target URL before I launched the test, change the number of simulated users or make other relevant changes.

Running repeated load test as part of your CI solution will reveal a lot about how an application’s performance is affected by all those small decisions.

Note that you probably don’t want to run a full set of exhaustive performance tests at every build. I recommend that a few well-selected tests are executed. The key is to get a series of measurements that can be tracked over time.

Related articles

• Automating Load Testing (developer.rackspace.com)