Julien Le Dem

CTO and Co-Founder, Datakin

Julien Le Dem is the CTO and Co-Founder of Datakin. He co-created Apache Parquet and is involved in several open source projects including OpenLineage, Marquez (LFAI&Data), Apache Arrow, Apache Iceberg and a few others. Previously, he was a senior principal at Wework; principal architect at Dremio; tech lead for Twitter’s data processing tools, where he also obtained a two-character Twitter handle (@J_); and a principal engineer and tech lead working on content platforms at Yahoo, where he received his Hadoop initiation. His French accent makes his talks particularly attractive.

Past sessions

Summit 2021 Observability for Data Pipelines With OpenLineage

May 28, 2021 11:40 AM PT

Data is increasingly becoming core to many products. Whether to provide recommendations for users, getting insights on how they use the product, or using machine learning to improve the experience. This creates a critical need for reliable data operations and understanding how data is flowing through our systems. Data pipelines must be auditable, reliable, and run on time. This proves particularly difficult in a constantly changing, fast-paced environment.

Collecting this lineage metadata as data pipelines are running provides an understanding of dependencies between many teams consuming and producing data and how constant changes impact them. It is the underlying foundation that enables the many use cases related to data operations. The OpenLineage project is an API standardizing this metadata across the ecosystem, reducing complexity and duplicate work in collecting lineage information. It enables many projects, consumers of lineage in the ecosystem whether they focus on operations, governance or security.

Marquez is an open source project part of the LF AI & Data foundation which instruments data pipelines to collect lineage and metadata and enable those use cases. It implements the OpenLineage API and provides context by making visible dependencies across organizations and technologies as they change over time.

In this session watch:
Julien Le Dem, CTO and Co-Founder, Datakin


Apache Spark has become a popular and successful way for Python programming to parallelize and scale up data processing. In many use cases though, a PySpark job can perform worse than an equivalent job written in Scala. It is also costly to push and pull data between the user’s Python environment and the Spark master.

Apache Arrow-based interconnection between the various big data tools (SQL, UDFs, machine learning, big data frameworks, etc.) enables you to use them together seamlessly and efficiently, without overhead. When collocated on the same processing node, read-only shared memory and IPC avoid communication overhead. When remote, scatter-gather I/O sends the memory representation directly to the socket avoiding serialization costs.

Session hashtag: #SFdev3

Learn more:

  • Accelerating Tensorflow with Apache Arrow on Spark + bonus making it available* in Scala
  • Getting Started with Apache Spark on Databricks
  • Connecting Python To The Spark Ecosystem