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Comet Launches Kangas, an Open Source Data Analysis, Exploration and Debugging Tool for Machine Learning.

Comet + Metaflow: The MLOps tech stack that truly scales with your engineering team

Machine learning is experimental in nature. It’s more like research in a lab than it is like building traditional software. Regardless of the team size, it pays off to experiment quickly, fail fast and only invest in the best performing models. Over time, as the team and business matures, the wealth of knowledge accumulated is beyond what any team can manually capture. 

The iterative nature of machine learning works best when the systems and tools of record, the MLOps tech stack, scales well, is quick to set up, easy to use, and ultimately human-friendly.

ML requires omniscient note-taking skills and infrastructure. When thousands of experiments are run, it’s impossible for humans to do all the note-taking. The support that most ML Engineers need is to automate as much as possible. Clearing out the manual tasks will help them stay closer to the business problem and get more value out of their ML investments.

The simplest MLOps tech stack that scales

The landscape for MLOps tools is quite vast. The majority of enterprise customers typically incorporate just a few vendors in their MLOps tech stack, along with their home-grown tools. The fewer tools in a tech stack, the easier it is to integrate various systems and stay agile as the business matures. Choosing an ML tech stack that scales is as much about evaluating the vendor as it is the tool itself. 

The ML workflow with Comet and Metaflow

Together, Comet and Metaflow enable a team of 1, or a team of 300 ML engineers to easily build, train and deploy models to production.

Metaflow provides a simple Python API for defining the business logic of your ML workflow and how and where it should get executed. Metaflow also helps to version all code, data, and models. Metaflow has been battle-hardened at Netflix, supported by the wonderful team at Outerbounds, and has been used to power thousands of applications across hundreds of companies, such as 23andMe, CNN, and

Comet brings clarity and visibility into what is happening inside every workflow execution, allowing you to track and compare experiments in a user-friendly UI. See how enterprise companies like Uber, WorkFusion and The RealReal scale up ML with Comet.

Together, these complementary tools help make ML workflows more robust, reproducible, and observable, both during prototyping and production.


Start logging Metaflow runs with Comet

With just a few lines of code, Comet automatically gathers and logs:

  • Metaflow pipeline such as source code definition and environment variables
  • Metaflow steps which includes autologging of 15+ common machine learning frameworks and libraries with hyperparameters, metrics and code
  • Metaflow cards

Start by importing the Metaflow integration and annotating the Flow class:

from comet_ml.integration.metaflow import comet_flow
from metaflow import FlowSpec, step

class HelloFlow(FlowSpec):
    A flow where Metaflow prints 'Hi'.

    Run this flow to validate that Metaflow is installed correctly.


    def start(self):
        This is the 'start' step. All flows must have a step named 'start' that is the first step in the flow.

        print("HelloFlow is starting.")

    def hello(self):
        A step for metaflow to introduce itself.

        print("Metaflow says: Hi!")

    def end(self):
        This is the 'end' step. All flows must have an 'end' step, which is the last step in the flow.

        print("HelloFlow is all done.")

if __name__ == "__main__":

Once you’ve run some experiments, the Comet-Metaflow integration will track both the individual tasks and the state of the flow as a whole. This enables consistent vocabulary and visibility of data across both Metaflow and Comet. 


Once you’ve logged a Metaflow pipeline with Comet, here’s how you can add relevant panels.


Try out the simplest MLOps tech stack for yourself

Here are resources that you can leverage to get started: 

  1. Comet docs
  2. Metaflow sandbox
  3. Comet example (GitHub repo)
  4. Comet example in a Colab 

If you have any questions, our teams are available on Comet Slack and Metaflow Slack communities.

More features coming soon!

We are working hard to make it easier to use both Comet and Metaflow together. Stay tuned for part 2 of this announcement later this year. 

Boris Feld

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