HOSTING POWER: Everything you’ve always wanted to know about Datacenter management at Criteo!

By: CriteoLabs / 07 Feb 2017

If you are like me and have always wondered How, Where and What the Hosting team in Criteo R&D does, this article is for you.  Out of curiosity, I conducted this sit-down interview with Kevin Cawngally & Imane El Azlouk to know precisely more about what goes on in the day-to-day works of the team expanding and managing the numerous Criteo DCs (Datacenters) worldwide.

  1. Kevin & Imane can you briefly tell me about your roles at Criteo?

Kevin: I have been in Criteo for 4 years as a Hosting engineer. Working mostly as a project engineer on international deployments (US, Europe, Asia) in order to secure the huge growth of Criteo’s business.  This Infrastructure mastership gives us the ability to deliver our banners even more efficiently. Our team, part of the global infrastructure team, is responsible for prospecting the best Datacenters for Criteo, managing projects delivery on our Infrastructure (active equipment like servers & network gear, and passive ones like Cabling design) ; maintain relationship with suppliers and service providers. We work across R&D teams to collaborate on projects implementation ; provide performance ETA and financial KPI’s to the management and finance department of the company.

Imane: I am part of the Recruitment team in charge of finding the best talents for our well-known R&D. I joined the company a little less than 2 years ago as an R&D Recruiter. My tasks include sourcing (looking for good candidates), interview management & applications follow-up, hires etc.  I particularly also focus on hiring the best hosting engineers for Criteo.

Part of my job as an R&D Recruiter is to establish a strong working relationship with my clients (the engineers). This encourages a better understanding of our technical environment from the engineers perspective which helps me (and the other R&D recruiters) to find the best teams in our R&D to place our candidates. Another fun and rewarding aspect of my job (and recruitment team in Criteo) is that we are lucky to attend local and international tech events with the engineers to recruit and promote our jobs and company J.

  1. Interesting! How many people work in the Hosting team and how are you organized?

Kevin: The Hosting team is composed of 2 sub-teams of 5 people managed by 2 team leads. Our team has grown quickly from 1 people to 10 in 5 years.

Our team manages today, 16 datacenters which represents about 20 000 servers around the world including a Hadoop cluster with about 2000 nodes. The locations of our Datacenters have been strategically chosen in order to be closer to our publishers. In addition, this helps us to constantly keep an eye on innovations and Datacenter trends around.

Infra & Hosting team @R&D Offsite

  1. What are the missions of a Hosting Engineer? Who are your internal customers?

Kevin: Our mission starts with a need: to find the best datacenter for Criteo starting with an empty white room, to servers delivery, through network cabling design & set up. As one can imagine, we work closely with the Network and SRE teams for such big projects, they are actually our main internal customers.

Another big mission is : the capacity planning, which is on our side of the team. This means that we define how many servers we need to deploy during the year according to the budget defined thanks to the business forecast of our financial department.

You will ask  which servers ? The servers are also our responsibility including their customization according to the R&D needs and a non-vendor locking policy. Those flavors or configurations constitute our catalog in which different services are running into them. Once everything is validated and ordered, we deploy ! For each type of mission we manage, we use site until the reachability checks of the gear with a strict cabling design quality. The supervision makes us able to get a visualization of our rooms, power consumed, temperature and humidity. From those inputs, we can have a global reporting, or per site, or per rack… we refine the search much more if needed as this tool has a role of an asset manager. In addition, the environmental monitoring that we put in place in our rooms give us more info if the SLAs (Service Level Agreements) are respected (temperature or humidity for example).

On the innovation side, we can talk about the customization of the Power Distribution Units : they are designed to fit our racks composition in a way to have the best level of power monitoring, security, redundancy. We also have a role in the procurement process by negotiating contracts until the final validation, technically speaking. Of course we are helped by the procurement team.

These are our main day-to-day missions.

Optical Fibers Cabling

  1. Why did Criteo decide to manage its own infrastructure? What about Cloud?

Kevin: It’s an historical reason. 8 years ago, Cloud was not as developed like what we have today and this forced us to build our own Infrastructure. We can say that we built our “own cloud”. In addition, it gives us the possibility to keep the control of our own Infrastructure (sensitive for Criteo).

  1. Out of curiosity, do you mind telling me how many Datacenters you are managing today?

Kevin: We are present on 16 DCs across the world. 10 DCs in which we are hosting servers (covering America, Europe and Asia). 6 network PoP in order to connect to key operators and multiple telco carriers to have the best redundancy.

  1. Imane, I see you’re nodding your head, do you also manage a Datacenter as a recruiter?

Imane: (Smiles) No I don’t, but I had the chance to visit one of our DCs in Paris during an onboarding session as all newcomers in the R&D are invited to visit to discover Criteo’s racks, servers, cold corridors, etc.,. And trust me, it was the experience! We also had an explanation about the network systems. It was very impressive to enter this big secured building. We were like kids again!

Onboarding session for R&D engineers at PA3

  1. You mentioned earlier your Datacenter locations are selected to bring you closer to your publishers. Are there other reasons?

Kevin: Once the location is defined, we need to find the best datacenter through a RFP (Request for Proposal) in which 200 questions are asked. Actually, we should not be far from the office or subcontractors in case an issue occurs. Another important point to note, we must take in account the growth of Criteo and choose a location where we can extend our infra in the future. We are always looking for specifications such as a high quality of uptime, high security and latency performances, SOX compliance and more.

  1. Do you think that your job is different compared to what’s done in other companies?

Kevin: I am not sure that in other companies you’ll find a Hosting Engineer. In addition, at Criteo, the context of management is different: we are managing 16 DC from Paris only.

For a R&D company, we are fortunate to have a budget for a lab, innovations and new technologies. One of our next attractive project is to industrialize our deployments by shipping racks fully equipped with servers, switches, PDU (Power Distribution Units) wired in advance which is a major step forward.

We also have others examples of sexy projects and technical priorities for 2017 :

  • New generation frames: Ready to use cabling
  • Open compute project: Design our own gear
  • Sharing: We are proud of what we have been building in the past years. This wouldn’t have happened without technology watch. We really think that we can contribute for the society by sharing our experience and helping others companies growing. Our team is happy to share with people in the industry through workshops, meetup’s, etc.

Last but not least, the big dream of our Head of Infrastructure is, in the future, to build our own Datacenter and create our own campus. However, this is a completely different job!

We may call you one day and ask you to help us for another kind of building project to talk about! J.

     9. Imane, are the above points mentioned by Kevin what you use to attract talents? What’s the recruitment process like?

Definitely! Working within an R&D department in an international context is not offered to everybody. As Kevin said previously, they are very fortunate to have budget for innovation and to work with different engineering teams. The hosting engineer role is quite broad: project management, technical requirements, technology watch, budget management (or budget only because they are very autonomous on this part!).

Criteo R&D also offers a good environment with onboarding’s for newcomers, career management that makes you evolve in your role and within the R&D (mobility’s, voyagers etc.).

As an individual contributor, you can also attend programs like Hackathons, 10% Fair… which are all great avenues to launch new projects and ideas that can contribute to the company’s growth.

Development programs like the Voyager can also contribute in helping other teams in their projects. It was very insightful for me when we had the Manager of the Hosting Team as a Voyager within our recruitment team. The role was new for me and by shadowing my phone screens and introducing the role in more details , it helped me to better target candidates and successfully hire for the team.

And by the way, we are still hiring!! (laughs)

The recruitment process includes a Phone Screen with the Recruiter and an afternoon of onsite technical interviews with the prospective team. This is the occasion to meet the teams and ask all the questions you may have!

Ibrahim: I think Kevin can actually tell us about his experience as an interviewer 

Kevin: The tech-hiring process is interesting and fair. It gives us the opportunity to meet candidates and evaluate them on their profile, technical and project management skills and cultural fit. If the candidate fits with the job, he goes to the “next round”, if not, he’s eliminated. Then, without talking with each other (to avoid being influenced by the other interviewer’s judgement), we have to write a consistent feedback to the R&D Recruitment team and give a score on 5 to justify our decision. The drafting of interview feedback takes a long time, however, it  encourages us to be more focused and prepared during the interviews.

Ibrahim: Demanding process indeed! I actually know very well the team in charge of R&D recruitments, and they go all out to find the best talents in the industry!

Thank you very much for your time, I can’t wait to hear from you soon about new projects your team will embark on!!

If you’re reading this article and want to join our hosting team, this job is yours. 

Article put together by:

Kevin Cawngally, Imane El Azlouk, Mohamed Benazza & interview conducted by Ibrahim Abubakari.

Kevin Cawngally

Imane El Azlouk


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