Last year marked the second edition of our internal event, the Criteo Developer eXperience Days, designed to elevate the developer experience by deepening their understanding of development best practices and tooling.
In a nutshell:
Why organize a conference? Well, we think it’s a good medium to share knowledge with a huge audience of developers. People go to conferences because they like learning things through talks and networking. The information shared is usually pretty packed, and you learn a lot in a short matter of time. It was totally appropriate for our goal: improving the developer experience by expanding their knowledge of development best practices and tooling.
We had a second hidden goal behind organizing the conference: creating a knowledge base with the slides and recordings of the presentations so that anyone could refer to them in the future. This is particularly true and useful for newcomers.
To delve deeper into the motivation and the experience of the inaugural edition, refer to this article by Michaël Sanchez 👇
Criteo DevX Days: why and how we organized an in-house event to improve the Developer Experience
This is the first article in a series where we will release selected content from our in-house conference.
medium.com
The inaugural edition was a resounding success, garnering positive feedback. Moreover, maintaining developer productivity remains pivotal in ensuring the delivery of our product roadmap. Thus, we were determined to organize a 2023 edition from Monday, October 16th to Friday, October 20th.
Our objectives remain consistent:
- Raising awareness about existing tools/services
- Acquiring new knowledge
- Enhancing existing expertise
- Facilitating discussions between service providers and users
- Building for the future
While our focus remains unchanged, we have carefully considered the feedback received from the 2022 edition and endeavored to enhance the overall experience for attendees.
👀 Evolution from the Previous Edition
✍️ Topics
Since Developer Experience encompasses a wide range of aspects, we anticipated that the conference would attract presentations covering various areas:
- Technical presentations encompassing tools, applications, services, and more.
- Workflow efficiency, including project bootstrapping, testing, release processes, and others.
- Culture and organizational topics such as onboarding, documentation practices, collaborative methods, time management strategies, and more.

Given that Criteo DevX Days is inclusive to all at Criteo R&D, our audience will be diverse, with participants from different backgrounds, including data engineers, infrastructure engineers, software developers, etc. To assist attendees in selecting the most suitable presentations for them, we have established distinct categories for presentations:
- Infrastructure and Security
- Developer tooling and development cycle (development/testing/release/troubleshooting)
- AI Machine Learning and Data Engineering
- UI and API development
🗓 Agenda
Unlike the 2022 edition, which adopted a hybrid approach, we embraced a fully remote format this time. Additionally, we standardized the presentation format to 30-minute talks (including Q&A sessions). This consistency allowed everyone to utilize the same setup (virtual meetings on Zoom) and resulted in improved recording quality, particularly in sound clarity, compared to previous editions.
Given the volume of proposals received, we created two tracks to accommodate all talks and devised a timetable that considered various Criteo locations. All presentations were scheduled between 3 PM and 6 PM Paris time (corresponding to 9 AM-12 PM Ann Arbor time and 5 PM-8 PM Yerevan time), enabling widespread live participation. Recognizing that it’s challenging to find an ideal timeframe for such events involving over 800 people internally, we made sure to share recordings afterward.
Moreover, spontaneously, we appointed a “Master of Ceremonies” for each track (Michäel and Kini) responsible for managing talk recordings, facilitating Q&A sessions, and maintaining momentum before and after each presentation. This impromptu decision turned out to be one of our best ideas.
⚙️ Platform
During the previous edition, we utilized Confluence as our internal tool at Criteo R&D to organize the event. However, we decided to explore an external solution specifically tailored to event management.
Kini, our Head of Developer Relations at Criteo, introduced us to the Koliseo platform, which had been successfully used to organize CommitConf in Spain. Although the platform offered features that were not necessary for us (such as ticketing), it provided valuable tools for managing the “Call For Presentations” process and creating the agenda.
We reached out to the Koliseo team to inquire about the possibility of using their platform for free for our internal event. Despite it being an unconventional use case, we proposed it as an experiment and offered to provide feedback. The team was receptive to the idea and provided assistance throughout the process, even when we encountered some bugs 😛
For the “Call For Presentations,” we were able to:
- Create tags corresponding to the presentation categories mentioned earlier. Each speaker was required to select a category when submitting their proposal.
- Configure general information for the “Call For Presentations” (e.g., deadline, description).
- Enable the “feedback” feature, allowing attendees to rate talks and provide feedback.
- Provide a simple form for speakers to describe their talk.

Regarding the agenda, we could:
- Establish tracks for each day.
- Define the timetable for each day, including both talk sessions and break slots.
- Assign each proposal to its designated slot.
Are you curious to know what the final agenda looks like? 👉 https://koliseo.com/criteo/criteo-dev-x-days-2023/agenda/0
We were highly satisfied with the platform (to the extent that we used it for another internal event) and plan to continue using it for future editions. A big shoutout to the Koliseo team! 👏
🤔 How did it go?
The feedback overall was positive, with people expressing appreciation for several specific changes:
- The Koliseo platform facilitated the collection of talks and publication of the agenda.
- Attendees valued the “only half-day” format.
- There was a noticeable increase in attendance compared to last year across both tracks, with approximately 50 to 60 attendees (minimum) connected simultaneously.
- The quality of the talks was well-received, reflecting our strong R&D Community and its impressive lineup of speakers.
- The 30-minute talk duration struck a good balance, neither too brief nor overly extended.
- We successfully identified a more suitable date than the previous year for the event.
- Each track/day had an MC responsible for welcoming participants to each talk and engaging in quick dialogue with speakers. When Q&A sessions were quiet, they prompted conversations by asking questions. For future events, we may consider using Slido to facilitate this interaction further.
- A fireside chat about DX featuring external speaker Abi Noda proved highly successful.
Additionally, during the retrospective session, certain “pain points” were highlighted. Most related to challenges within Criteo’s R&D organization itself (such as time zones and perceptions regarding DX being solely relevant for platform teams). These insights have been duly noted for consideration in future editions.
🗣 Numbers!
Let’s delve into some statistics:
- We received 29 proposals, which is 11 fewer than the previous edition.
- There were 36 different speakers scheduled for the event.
- The agenda included:
3 sessions focused on “Infrastructure and Security”.
15 sessions dedicated to “Developer tooling and development cycle”.
5 sessions covering “AI, ML, and Data Engineering”-
6 sessions centered around “UI and API development”.

In conclusion, the Criteo Developer eXperience Days has proven to be a valuable platform for enhancing the developer experience by expanding knowledge, sharing best practices, and fostering a culture of continuous learning and improvement.
The event has successfully achieved its objectives of raising awareness about existing offerings, acquiring new knowledge, enhancing existing expertise, facilitating discussions, and building for the future. The positive feedback, increased attendance, and the evolution from the previous edition demonstrate the event’s impact and the commitment to delivering an exceptional developer experience. Looking ahead, the future editions will continue to prioritize the diverse needs of the Criteo community, maintain high-quality content, and further enhance the overall experience for all participants.
The Criteo Developer eXperience Days remains a cornerstone in fostering a thriving developer community at Criteo. 👏




