Jelle Kalkman


Jelle Kalkman

Jelle joined us to develop the frontend of Semonto. He has a background in photography and holds a bachelor's degree in computer science. In his designs he has a special interest in user experience. When he is not working on a front-end project he is probably riding or maintaining one of his bicycles. Just like everyone else at Semonto he loves cats.

Hand on laptop keyboard

Tips and Tricks

Is poorly written code harming the performance of your website? (Here’s how to avoid the top 7 mistakes)

Your code tells your website what to do. If these instructions are flawed, the website can stop working correctly or even go offline. Here are some examples of how poorly written code can harm your website and how to avoid the top 7 coding mistakes.

Jelle Kalkman - 15 June 2023

A mock up of Semonto on a desktop background.


NEW: Improved notification settings, per feature

Some users have told us that they would like to manage notifications on a feature level in Semonto. We have been working hard to make that possible.

Jelle Kalkman - 1 December 2022

A mock up of Semonto on a desktop background.


What do you think of Semonto’s redesign?

Have you noticed that we gave Semonto a makeover? It is now easier to navigate between the details of the websites you are monitoring.

Jelle Kalkman - 17 November 2022

Desktop with downward chart

Tips and Tricks

What is the cost of downtime?

Is your business impacted when your website is temporarily unavailable? In this article, we help you calculate your total cost of downtime.

Jelle Kalkman - 3 November 2022

An illustration of Semonto on a desktop background

Tips and Tricks

An extra layer of security with HTTP response headers

We all use online services in our daily lives, for example for online shopping, filling out tax returns or checking health insurance. When we do, sensitive personal information is sent back and forth. That is why online security is so important. One easy way to increase the security of your website as a provider is to set up security headers.

Jelle Kalkman - 8 September 2022

Man holding phone with loading screen

Tips and Tricks

Optimise your website for a crowded internet

Especially now, with a lot of people working from home, the internet can get a bit overloaded. However, you still want your website to load fast because increased loading times have a negative effect on your bounce rate. In this blog, we discuss some tools and techniques to speed up your site and to reduce the network impact of your website on the internet.

Jelle Kalkman - 1 May 2020

Screen shot of team management dashboard in Semonto


New feature: Manage your teams in Semonto

We added a feature that allows you to give your team members access to your Semonto account without having to share your own login and password.

Jelle Kalkman - 09 March 2020

A mockup of Semonto Supervisor on a tablet showing the logs in an uptime report


New release: Added logs and improved test details

With this version we added logs to the uptime reports and improved the details of individual test results.

Jelle Kalkman - 16 February 2019

A mockup of Semonto Supervisor on a mobile phone and a tablet


Improved user experience, onboarding and more

We are happy to announce that we released a new version of Supervisor where we improved the user experience on multiple parts.

Jelle Kalkman - 18 December 2018

An illustrative image of an out of stock item.

Use Case

4 more content monitoring hacks in Semonto

In our previous blog post, we showed you how Semonto can watch for certain phrases on web pages. In part 2, we give you even more time-saving hacks using this content monitoring feature.

Jelle Kalkman - 24 March 2022

An empty browser screen on a desktop background

Use Case

4 Content Monitoring Hacks to Save Time

Semonto has a feature called content monitoring, which enables you to watch for certain phrases on web pages. In this article, we explain how you can use that to your advantage.

Jelle Kalkman - 24 February 2022

Screenshot of a status page


Improved Status Pages: Add your logo and choose how much you share

We added some extra customisation options to our status pages. You can now add your logo and determine the level of detail you want to share with your readers.

Jelle Kalkman - 15 June 2020

Mockup showning the Semonto Supervisor on a laptop


Introduction of contact groups in Semonto Supervisor

We made some major changes to how to configure how Semonto warns you when issues arise. These configurations are now much easier to reuse and adapt for multiple monitors and pulsechecks.

Jelle Kalkman - 15 October 2019

Mockup of Semonto on a desktop


A recap of the latest improvements to Semonto

In the past year, we have added some new features to Semonto, and we are always working to further improve the tool. Let's give you a recap, followed by a sneak peek of what's still to come.

Jelle Kalkman - 16 June 2021

A screenshot of a status page made with Semonto Supervisor


Improved status pages

We are happy to announce a new version of Supervisor with improved status pages.

Jelle Kalkman - 30 October 2018

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