Technical Marketing Handbook Podcast with Simo Ahava

TMH #5: Tag Management with Adam Halbardier

In this episode, Adam Halbardier of Google joins me to discuss tag management. We talk about the difficult engineering choices that the developers of the world's most popular tag management system face every day.

This is a special episode for all you Google Tag Manager geeks out there!

My interview guest this time around is Adam Halbardier of Google. Among many other roles, he leads the server-side tagging team for Google Tag Manager.

In this interview, we started casually with server-side tagging, a new-ish paradigm for Google Tag Manager, where the tagging logic is moved to the server rather than kept as a burden on the client.

This then spiralled, of course, to exploring the engineering decisions that come with such an incredibly popular service. We discussed the role of security, performance, and feature design.

GTM isn’t perfect, and Adam rightfully recognizes that. However, I’ve personally always considered GTM to be somewhat different than the other services and tools maintained by Google.

For one, it facilitates data collection rather than collect data in itself. This is all the more emphasized with server-side tagging, where the pitch is how it improves the governance and oversight opportunities for those data flows that would otherwise go from the browser directly to the vendor, unchecked.

Another aspect of GTM is how it’s always been a community product. I’m not saying the community built it, but that the community around GTM has been instrumental in making it a better service. The custom solutions, templates, and guides that are created and shared continue to improve the GTM experience for all users, not just those who pay the money for premium membership.

Listen to the episode using the player or find it in your favorite podcast service.


  • 00:00:00 – Introduction
  • 00:06:40 – Adam explains what server-side tagging is.
  • 00:08:20 – How important was it to make Google Tag Manager’s server-side tagging 100% owned by the company running the site rather than turn it into a SaaS rented from Google?
  • 00:09:37 – The default deployment runs on Google Cloud, and it downloads containers from Google servers. Is the server-side tagging setup REALLY owned by the customer and not by Google?
  • 00:10:57 – Is server-side tagging a completely separate thing to client-side tagging? Is it complementary, or is it designed to replace web containers?
  • 00:11:58 – What prompted Google to enter the server-side tagging space?
  • 00:13:21 – Do you think server-side tagging is mainly about “getting data back” from browser tracking protections and ad blockers that infringe upon it?
  • 00:14:45 – How do you decide whether to focus on generic APIs that could service all vendors and all endpoints vs. Google-specific APIs that are designed specifically for Google’s platforms (e.g. ads, analytics)?
  • 00:18:08 – Are Custom Templates today the bridge between Google Tag Manager users and the engineers? Is there some other form of “community”, such as what existed back in the day with Google+?
  • 00:20:23 – Do you think there’s an adoption problem with some of the security & trust measures that Google Tag Manager has released over the years?
  • 00:22:14 – Governence is often perceived as a bottleneck to get things done – do you think an organization that is high-governance can’t really run GTM efficiently?
  • 00:23:09 – How do you decide whether to build for beginners vs. for power users?
  • 00:24:57 – Where do you think GTM sits best in today’s organizations? Is it still “just a marketer’s tool”?
  • 00:26:46 – How considerate do you need to be about performance impact when designing features for GTM?
  • 00:29:18 – How do you deal with the increased opaqueness of tracking that’s come with server-side tagging, now that much of the data flow is moved to the server?
  • 00:31:42 – Are there features being designed that could increase transparency when using server-side tagging? Perhaps some type of response mechanism back to the browser that would detail what happened in the server?
  • 00:33:53 – What are some of the big things in GTM’s roadmap for the near future?
  • 00:36:05 – How do the consent settings in GTM relate to Google’s Consent Mode API?
  • 00:36:54 – Will consent configurations be available in server-side containers too?
  • 00:37:30 – If you could change any aspect of GTM at the snap of your fingers, what would you change and why?
  • 00:39:33 – Outro

Notes and references

Hide picture