AI Engineer Europe 2026
Does GenAI "belong" to data scientists?
About this talk
Braintrust solutions engineering leader Phil Hetzel argues that generative AI and agent development should not belong exclusively to data scientists or machine-learning platform teams. Contrasting traditional enterprises with cross-functional AI-native teams, he explains that foundation-model providers already handle model training, shifting application development toward prompts, context, evaluation, observability, and production feedback informed by human judgment. Audience questions explore organizational boundaries and closing the evaluation loop.
Chapters
- 0:00Who owns agentic development? Speaker and Braintrust introduction
- 3:06Traditional enterprises versus cross-functional AI-native teams
- 5:13Pretrained models, application evaluations, prompts, and context
- 12:47Broad participation in AI product development
- 15:40Audience questions and closing the evaluation feedback loop
Talk transcript
- 0:00
[upbeat music] What we're gonna do today is we're gonna talk about whether agents or agentic development really belong to, uh, data science or machine learning engineers.
- 0:24
How many people here would describe themselves as either, A, a data scientist, or two, or, or B, a machine learning engineer? Okay. This is gonna be awesome. I'm glad that no one has brought any rotten tomatoes because the, the answer that I'm gonna give is, is probably not gonna be exactly to your liking.
- 0:41
But give me a chance to justify why. Um, what we're gonna do today is talk through, uh, these couple things. I'll introduce myself, introduce the company that I work for, and then, um, we'll get in, in- into the topic.
- 0:55
I'll probably rip through the, the slides pretty quickly and hopefully give some time for, uh, for Q&A. Um, but before I do that, I'll introduce myself. My name's Phil Hetzel.
- 1:04
I lead the solutions engineering team at Braintrust. Um, Braintrust, uh, well, I'll, I'll, I'll go over that in a second, but, uh, the solutions engineering team is basically, um ...
- 1:14
I think there's a, there's a seat, uh, right there. Yeah. Um, solutions engineering team is basically the people that allow our customers to get the most value out of the platform as quickly as possible.
- 1:25
Uh, prior to Braintrust, I spent 12 years in consulting and systems implementation. Um, my last role in consulting was leading the global Databricks business unit at a company called Slalom Consulting, and I noticed that a lot of my customers were really prolific at creating generative AI proofs of concepts, but not nearly as good at bringing those proofs
- 1:44
of concepts to production. So I started using Braintrust as a user first, and I liked the product so much that I applied for a job, and I've been here for about a year, uh, since, since that happened.
- 1:55
Outside of work, I like to play chess, but I'm not very good at it, and I like to spend time with my wife and my dachshund, Pistol Pete. Uh, he's, he's pictured over there.
- 2:02
He's the one in brown and not the one in black. The one in black is me. The one in brown is him.
- 2:07
Uh, what is Braintrust? Braintrust is a, um, agent quality platform. The way that we perform agent quality is, uh, two different pillars, evals and observability. Evals, those are the things that you're doing, um, in experimentation as you're tweaking and building your agent to become confident in your agent's execution once you push it to production.
- 2:30
Obser- agent observability to us means that once it is in production, that you remain confident in its execution once it's confronted with real usage and real users. There are other some, uh, other ancillary things that the platform does, but in general, that's what we do.
- 2:44
Uh, I'm really not gonna talk about the product today. If you're interested about the product, uh, you can find me at, uh, at the booth downstairs. But other than that, very happy to get in, into the content.
- 2:54
Um, just some observations that, that I've seen, uh, through, through the last year of, of watching some of the top, uh, teams building agents a- a- across many different industries.
- 3:06
I think there are, there are, like, two different types of organizations that we work with. There's the traditional enterprise and there is the AI natives. Traditional enterprise approach agent, a- uh, agentic development a little bit differently than AI natives.
- 3:21
Traditional enterprise, the, uh, a person in charge, a person of note, CEO or CIO, will read something in the CIO or CEO monthly magazine that says that they need to be building agents, and then they'll tell their delegate that, "You need to be building agents because that's the thing that's going to take us to the, to the
- 3:38
AI promise land." And then that will get further delegated to an existing ML or data science platform team who already have a lot of the tooling in place, and since generative AI has AI in the name, it's a pretty natural fit to hand over that capability to an existing AI or, or data science team.
- 3:58
Is anyone kind of in the, in that bucket today where they just got ... They were machine learning platform engineers previously, and they just kind of got handed generative AI because that's kind of seemed like the be- best fit?
- 4:09
Yeah, got it. And I, and there, there's no judgment or connotation here. Uh, d- just, just something that, uh, that, that I've, that I've observed. Uh, there's an, a whole other set of companies that are, that are more AI native that think less about, uh, what already exists because nothing really existed before generative AI, uh, started to
- 4:28
gain popularity for these companies. In fact, they started building their entire offering around agents. So rather than having an, uh, AI ML platform team, they'll just have a, a small team of engineers that are, um, agile enough to grow with the times and, um, you know, rather than having very specific segments of things that they do, everyone
- 4:51
is, is very much cross-functional across both product engineering and AI engineering. Uh, the other thing that, that's interesting about these AI natives is that since it's, since these are typically smaller companies, that each person has more proximity to the problem, i.e., they have a better understanding of what the end agent is actually meant to solve.
- 5:13
Uh, two different, uh, differences, uh, between traditional ML and generative AI. The model's already built. So much of, of, of what data scientists and machine learning engineers is going through that data pipeline of training a model.
- 5:27
What do we do when the, the model is already built? And the other interesting thing, or other interesting nuance, I should say, is that if you want to add value to these models, then you can add values not necessarily with feature engineering but with natural, natural language, which could bring in a different skill set to the, to
- 5:43
the conversation. So just to make this, uh, more clear, this is like ... I, I know that it's so much more complicated than that. But abstracted to a certain level, this is kind of what data scientists and machine learning engineers do, is a data pipeline of training and testing, making sure that you're not over fitting, eventually deploying
- 6:02
that model where it can be used by some downstream product team. That is, that is, that is kind of what data scientists and machine learning engineers are used to doing.
- 6:11
This, though, has already been done. Anthropic and OpenAI and Mistral, they've already done the, the data process of, um, grabbing that data, putting it through the pipeline, training the underlying LLM, and then deploying it through an endpoint so that their consumers can use it.
- 6:29
Um, the one nuance here is that instead it f- you know, while Anthropic and OpenAI and Mistral will be doing testing of their own, we still need to, as, as, uh, AI teams, we still need to perform evals after we've implemented, uh, those APIs in- into our product.
- 6:48
That's very, that needs to be very important to us. That's really the only nuance here between these two images. Um, how do you change the ... This is kind of going, uh, uh, to, to these two differences before.
- 6:59
The second difference, how do we change these predictive applications before and after? Uh, traditional ML, you, you either add more data to retrain it or you're performing feature engineering to adjust how the, uh, how the underlying model is performing, and then you're performing a lot of AB testing to understand how your model, uh, is, how your model
- 7:19
changes has provided lift or not provided lift. Um, with generative AI, you can, since that model is already trained, and irrespective of performing any fine-tuning on that model, which is pretty rare, um, the way that you can change that behavior is just by changing the inputs, the prompts, the context that you're giving that, that model.
- 7:38
So there's a lot of folks that will be performing com- context engineering on top of these models and, uh, those folks could have a better understanding of how real users could be using the agent, they'll have closer proximity to the problem.
- 7:52
Uh, so I'm gonna make the case for and, and against agents belonging to, uh, to data scientists. Uh, let's say I was making, I was debating, uh, the position of it really does belong to data scientists and traditional machine learning engineers.
- 8:08
Uh, agents use models. In our organization, models are go- are governed by data scientists. So, uh, data scientists will have a lot of underlying knowledge about how neural nets work and, and thus how LLMs work.
- 8:23
Um, because of that, they're going to have a far better appreciation of the risks inherent with using this very complex technology. Um, other, other, other thing here is that they'll have very rigorous processes to push models and model assets to production.
- 8:41
They will understand some type of testing process that they can use to keep the company safe and make sure that us- end users are getting the, um, the, the experience that they need.
- 8:53
Um, and then number three, very related, just very rigorous mindset around testing. The counter report to that is, again, model's already built, so we d- um, we don't necessarily need to do any training and testing.
- 9:05
Um, uh, entirely different, uh, different pipeline. We're not doing, like, the whole, uh, cross-validation dance. And this is probably the biggest argument. Um, d- does an AI, or sorry, does an ML engineer or a data scientist really know what they're testing for?
- 9:21
One of the things that, uh, I've noticed with some of these teams is they will really lock onto the traditional ML engineer metrics like precision recall, F1, um, and they'll obsess over those metrics because that is what has gotten them there up to that point.
- 9:36
But when you're, uh, analyzing agents, it is far broader of a surface area that you need to be evaluating. You need to be evaluating the functional, uh, performance of that agent rather than just a technical performance across that toolbox, um, that we're, that we're tr- traditionally used to working with.
- 9:55
Um, so argument here is, let's say that I was arguing that agents belong to non-data scientists, which could be both technical and, and non-technical experts. We could make the case that LLMs are just APIs.
- 10:08
Product engineers are very used to using APIs as they, as they build applications. Um, that is a, a massive part of what they do, is reaching out, grabbing information from another system based upon some payload, and bringing that information back in a way that's useful to the end users.
- 10:26
That is a, that is a thing that product engineers do. Um, the other thing about agents that is unique is that if you have a very complex agent, it could be running across many different types of compute if it's, if it's some distributed agent, i.e., you have a supervisor agent up here and then it's calling different, uh,
- 10:45
child or sub-agents that might be running on different infrastructure. And as they're running on different infrastructure, they might be calling different systems as a result. That's a, that can be a very complex systems problem that might not be up the alley of a, of, of someone with more of a, a s- a statistics or maths background.
- 11:05
And then finally, um, more on the, on the non-technical side, it's really valuable to have, uh, subject matter experts or product managers be able to control the actual prompts that we're seeding the agent with.
- 11:18
These people are the ones that have the most proximity to the problem that the agent is trying to solve. So there's a lot of lift in having a non-technical person have a lot of say in how the agent performs.
- 11:31
Not only that, there is a, um, there can be a l- a, a very large human annotation workflow that goes into making great agents, where as you see these interactions, if you are a non-technical person but has a lot of domain expertise for how the agent is supposed to be performing, uh, that non-technical person can look into
- 11:51
an agent trace and describe whether or not the agent is performing well or not performing well, and most importantly, why that's the case.
- 12:00
So where I'm landing with all this is not that all of the people that raise their hand that says, "Yes, I am proudly a data scientist or ML engineer," I am not going to stand here and say, "Well, guess what?
- 12:11
Like, you need to completely, um, refresh your, your skill set." Um, that would be a very, uh, silly thing to say 'cause I kind of figure there would be a lot of data scientists in the room, and I'm, I'm at least smarter than that.
- 12:23
But, um, it, it does make sense to have a very diverse team when you're, uh, when you're building these platforms. Um, it makes sense to bring both non-technical and different types of technical people into the fold.
- 12:36
How can data scientists add value to building agents? Um, a couple different ways. Al- also, all these ways are irrespective of actually helping to build the product itself. I think that's inherent.
- 12:47
Um, with, with the tools that we have available to us now, it's actually quite easy for us to be able to add value to a product even if you are not coming from a product engineering background.
- 12:58
But what I think is really valuable is data scientists can add, um, to, to use an overloaded term, add the guardrails to this process. A lot of people are very aggressive in, in how they implement LLMs.
- 13:08
They don't understand how the underlying technology works. They don't come from a stats background. I think data scientists can, can be the adult in the room, uh, during those situations and say, you know, "The, the LLM, this is how it's trained.
- 13:21
It's just predicting token after token. It doesn't actually know anything really. It's just a bunch of stats problems at the end of the day." I also think that, uh, LLM as judge is a huge part of the eval process when you're building agentic applications.
- 13:37
Um, again, people are very tempted to just believe LLM as judges when they're performing evals. They're just prompts and models at the end of the day, and it's very easy to be able to create some label data set and perform the traditional recall precision and F- F1 style metrics on those, which, um, data scientists will have expertise
- 13:56
to. And the last, last one, this is the most technical one, of course. If you do need to fine-tune an open source model very specifically to your use case, that's probably gonna be, like, the most fun and, and technical thing where, uh, data scientists and machine learning engineers can, can add a ton of value.
- 14:13
Um, the ideal mix here, i- in addition to the, like, to, to that top section, we want, uh, both product application and systems engineers to be able to implement those requirements into the product itself, um, that, that the non-technical, uh, experts are, are giving to them.
- 14:30
Uh, we wanna make sure that the systems that we're building around these agents, i.e. where the agents are executing, is, uh, such that it's going to lead to a great pro- um, user experience.
- 14:41
And then finally, and this is probably something the, the data scientists can pitch into as well, implement actual eval and observability pipeline so you have that feedback loop of what happen, what is happening in production and what is, uh, and what's happening in experimentation.
- 14:55
For non-technical experts, we want them to be performing a ton of human annotation and a lot of prompt and context engineering. They have the closest proximity to the problem.
- 15:06
You need to bring them into the fold if you wanna have a very relevant a- agent to your use case. Uh, so what's next? Uh, answer is always in the middle.
- 15:15
Um, so I, I hope I didn't fully insult half the people in the room today. Um, if, uh, if I have, then you can feel free to, uh, come to my, come, uh, come to the Braintrust boo- booth and give me an earful.
- 15:26
That's completely fine. Uh, but the idea here is that ton of value for data scientists. Just make sure that you're bringing more folks into the room as you're, uh, as, as you're building agents.
- 15:35
Two minutes for questions. I know that we're keeping, like, a very tight timeline. Yes, sir.
- 15:40
Um, yeah. Re- really good. Um, I, I,
- 15:44
like, the, the, the conclusion.
- 15:46
Mm-hmm.
- 15:46
Uh, uh, but I, I do have a question on the, the framing. So, you know, this ... I, I view agents as a tool.
- 15:52
Mm-hmm.
- 15:53
So anybody in the organization could, could, you know, build and own an agent-
- 15:57
Mm-hmm
- 15:57
... in theory. Um, uh, and they, they may have more domain expertise in the data science or the, the engineering side.
- 16:04
Mm-hmm.
- 16:04
Um, uh, g- rath- rather than thinking about who owns the tool-
- 16:09
Mm-hmm
- 16:09
... you know, this is a machine learning team or that's the computing team-
- 16:12
Mm-hmm
- 16:13
... that needs to work up, h- how do you, how do you view it as thinking about it based on the problem that's being solved and seeing agents as a tool to solve the problem rather than the, the agents as the solution itself?
- 16:24
I think you're thinking about it, I think you're thinking about it the exact same way. It's a, it's a product that a, that a diverse team builds. I think the mistake that I see a lot of typically traditional companies make is they say, "Oh, this ...
- 16:36
We're making another predictive model."
- 16:38
Yeah.
- 16:38
And they isolate it to the ML engineers or data scientists and say, "Go build an, go build these agent things." Um, I think we're, we're actually thinking about it very-
- 16:47
Yeah
- 16:47
... very similarly.
- 16:48
Great. Cool.
- 16:48
Yeah. Maybe w- uh, time for one more question. Yes.
- 16:51
Um, yeah. I, I really, um, echo with, um, yeah, the message that you're trying to say. I don't know if I can cross-function it, but I, I, I think I'm just curious about the, um, actually the tooling that you are offering about closing the loop.
- 17:05
Mm.
- 17:06
And, um, I think that, uh, at least from my experience, the missing delta is the tooling to facilitate that enter ... like in traditional machine learning, but into enter like, um, variation and then making.
- 17:18
Mm-hmm.
- 17:19
Uh, is that something that Braintrust is, like, thinking about?
- 17:23
Yeah.
- 17:23
Is c- yeah, like how to, um, make it easy for a domain expert to update the system and
- 17:30
Yeah, for sure. Yeah, there's a, there's a lot of things that we do to lean into that domain expert persona. We do have a human lab- labeling component as a part of our platform, and we do have, like, a, a agent and prompt playground where people can experiment with their own prompts and send them to the underlying
- 17:46
agents themselves.
- 17:48
Right.
- 17:49
Yeah.
- 17:50
Yeah. Um, uh, but I mean the, um, like how to ... How, what is the system in play that you keep the evaluator up to date, but then also the system up to date and, like, understanding it?
- 17:59
Like, uh, I guess the error analysis, like if the error is based on the evaluator or the system itself.
- 18:05
Mm-hmm. The idea is that we, we gather data from production to continually add to that offline data set that we're evaluating upon, and then hopefully we're, uh, gaining grounded data along the way where we can kind of self-check ourselves to understand, um, if our evals are aligning, starting to align more to human, uh, agreement, agreement or, or
- 18:29
not, or if they're diverging. Yeah. Okay. Uh, everyone, that's my time. I really appreciate the attention today. If there are any more questions, find me downstairs. [clapping] [upbeat music]