Interview with Stewart McGrath, CEO of

Categories, a startup founded in 2012, is a pioneer in the emerging DIY CDN (“DIYs” ) sector, enabling enterprises of all sizes to build localized or global content delivery functionality into their web application test and production environments. Prior to’s launch, the company decided to focus its research and development efforts on  the application layer, and instead of building out PoP infrastructure, rather take a more unusual approach and leverage the strengths of the AWS, Azure and Google infrastructures.

The DIY trend plays nicely into the Multi-CDN setting, allowing CDN Buyers to use 3rd party CDN’s as well as their own flavor of CDN. DIY’s are not a replacement of a full services CDN, although in specific instances, it can be; rather DIY’s are an option for DevOps folks wanting to install Varnish, ModSecurity and Advanced Reporting into their virtualized settings.

A big thanks to Stewart McGrath for the interview.

How did you come up with the idea of

As the CIO of a major ecommerce player, we were frustrated buyers of CDN services. We loved the promise of speed, security and scalability that CDNs provide, but we had an agile development practice.  The old school waterfall deployment model of existing CDNs just didn’t mesh with our development practices.

Our development team rightly wanted the Dev environments to be as close as possible to production so that all the mistakes could be made in Dev with a fast feedback loop.  Our engineers did not want to make changes directly in production to the CDN or promote code to production (or even test or staging) that had not been checked against the CDN in Dev.   They did not want to find themselves standing around during an incident saying, “but it worked on my machine”.

This made sense to Dan (our co-founder) and myself, and we began questioning why CDNs had not moved with the modern forces of software development – Agile and DevOps.  We concluded that it was due to the network focus of the existing CDNs.  They all followed the same Network build and “black box” software principles that Akamai pioneered 18 years ago.

We figured if we approached the CDN space with a software first mentality, we could give developers easy access to control over the CDN.  They could have a CDN that aligned with their normal software development processes and in this way get the most out of the CDN.  Engineers could avoid those production issues when code deployed clashes with the CDN.  No more “it worked on my machine” moments.

Is CDN for Agile a new trend and what leads you to believe that?

Reverse proxies are a smart way to add value to a web application, whether that be security, performance or scalability.  We are confident that they will continue to be so, but also believe that they must be relevant in an Agile world.  With the majority of web shops now embracing Agile methodologies, CDNs are increasingly drifting away from mainstream processes.

Akamai’s network was built 18 years ago when it made sense to run a waterfall CDN deploy alongside a waterfall software build.  The CDN industry has entirely followed Akamai’s suit and built black box networks, which support waterfall deployments.

CDN for Agile is a new trend. is the only CDN around that is hooked up to provide an immediately seamless integration with Agile development workflows.  Backed by Git and with the same, open, real time logs and metrics stack in Dev, Test, Staging and Production, developers and engineers have all the right tools to manage the CDN completely.

Static object caching is boring and we all know that the biggest bang for buck when running on a CDN is when you have the application well integrated with the CDN.  More HTML offload and more tailored WAF rulesets can be run when this is the case.  The best place to integrate the application with CDN?  In development, not in production.

What is required if an ecommerce company is interested in a global CDN?

All you have to do is sign up and choose what you want to run in your CDN (e.g. Varnish Cache plus ModSecurity).   Our platform then spins up the user’s complete CDN globally, on all AWS or Azure infrastructure, in just minutes.  It is ready to go out of the box and with SSL and HTTP2 support, users can gain instant wins just by making the DNS change which then pushes traffic through the platform.

If the user wants, they can git clone the CDN to whatever local environments they like – Development, Staging, etc.  Build, test and deploy to production and make your DNS changes.

What products do you offer now?

Our customers can choose Varnish Cache 3, 4, 4.1 and / or ModSecurity.  We provide the open source reverse proxies so that users can take advantage of all prior art on the Internet on how to get the most out of these reverse proxies.  None of our reverse proxies have been forked so users know exactly what they are using and will not be caught out on old reverse proxy versions.

Because our customers are all running their own CDNs, we don’t have the ugly upgrade paths that other CDNs have with their proxy stack.  Our customers can choose when they want to upgrade while we do all the heavy lifting.

We provide instant cache ban and APIs. also includes a massively open alerting system built on Umpire so that our customers can integrate alerts easily with their existing synthetics alerting tools, such as Pingdom, Site 24×7 or New Relic.

Our customers also have access to a real-time logs and metrics stack built on Elastic Search, Logstash and Kibana plus Graphite and Tessera.   We log every request through the platform and serve them back to users enriched with elements such as GEO location and user agent.

Again, these are open source products and we have not forked or locked them down, so if you can drive Kibana, you can drive our logs platform.  The end points are open to users so that the data can also be pulled from our platform directly into our customers’ metrics platforms.

What products are you coming out with in the next 12 months?

We publish a library of reverse proxies, therefore any reverse proxy is fair game to come onto our platform.  While we have picked Varnish Cache and ModSecurity as the first proxies to arrive, more are on the way.

Google’s PageSpeed module is a great option for FEO, Nginx with LUA rewriting for massive edge flexibility, HAProxy for load balancing etc.  We also have seen interest in some proprietary proxies being run on our platform for higher bandwidth activities such as video streaming. And finally, Varnish Cache 5 is due out this year so we will roll that onto the platform as an option too.

Given the immense flexibility and open nature of our platform, we also have some category killer features lined up which are… Nope, sorry, can’t say yet!

Is Google CDN a threat?

Sure, Google CDN is a threat to the rest of CDN Land as they have run up a CDN in the same way as all the other CDNs.  Network focus first rather than software.   They will be running the same race to the bottom on bandwidth pricing in which the rest of the CDNs are caught.

Unless Google provides a seamless workflow integration for Agile development teams, however, it is no different to all the other CDNs in terms of posing no real threat to

Scroll to Top