DataMass Summit 2019, Gdansk, Poland

Jacek Laskowski
3 min readOct 6, 2019


Thanks Jakub Wszolek, Mariia Ruban and the entire conference crew for DataMass Summit 2019 conference in Gdansk, Poland on October 4th, 2019. I was invited as a speaker and enjoyed it a lot.

Me at DataMass Summit 2019

Not only could I give the talk about “Modern Stream Processing Engines Compared — Kafka Streams VS Spark Structured Streaming” (my lovely ones), but also had an opportunity to have a word with the attendees. It turned out that there is quite an interest in these two stream processing engines and the obvious question came up fairly often “which one to use and when?”

The conference was different from the others for a couple of reasons (and I really hope they all can help me becoming an even better speaker at the conferences to come, e.g. Spark + AI Summit Europe 2019 in Amsterdam in two weeks).

Me at stage and the audience

Google Slides

First and foremost, I used Google Slides for the slides. I think it was my first conference where I used it as I’ve always been a big fan of reveal.js as the presentation framework. Partially because it’s more geeky (i.e. hard to get right), but more importantly slides become “the code” that can be versioned (see the slides for the Apache Spark and Apache Kafka workshops of mine).

You can find the slides at SlideShare.

Google Slides gives much pleasant presentation experience not only at design time, but also at presentation. It was so much quicker to get slides right and fix whenever needed. Think I’ll stay with Google Slides for a bit longer (yet the versioning is very important to me). For the time being, SlideShare should work fine.

Let me know if you’ve got any further questions. Consider the current version “DataMass Summit 2019” and expect new versions soon (as I’ve got this talk scheduled at BeeScala 2019 and Bydgoszcz JUG’s meetup).

Presentation Challenges

I had to hand over the slides before my talk.

I’d never done it before so I wasn’t sure how it’d go. In case of any troubles (and they could happen at any time as the presentation gods are lurking in the shadows) I’m simply doomed and no way to recover.

And once I started the talk, while at the stage, the mic, the clicker and the slides simply decided to disobey. Think of me at the stage, ready to talk with no mic, no laptop, no slides. Just me and the audience.

What a fabulous experience!

As much as I was scared to have been in such situation, it was pretty funny. It was certainly not my fault and could easily build confidence that all future problems as simply not mine! A pretty comfortable situation, isn’t it? I’m sure any speaker would love it. No more issues that could be yours. All is theirs!

Relieved with the beginning, I started my talk with no slides and the mic (that we fixed in the meantime). The slides were coming.

So the very first 5–10 minutes were just me at the stage speaking with no slides and I enjoyed it. I’m not so sure about the audience, but the feedback was positive.

Eventually the slides appeared and I moved on. Did I say it was my first time with the slides elsewhere? Anything I could share with the audience had to be on the slides or in my head. I had no way to switch to spark-shell or IDEA and try to show even more (which would probably not work whatsoever).

And since I had my brand new MacBook Pro 2019 with USB-C ports only I actually expected other troubles that did not have a chance to happen this time.

Conclusions (aka Lessons Learned)

  1. Be ready to hand over your slides at any time (to free up your mind)
  2. Use Google Slides and SlideShare

Let me know how to make the materials and my future presentations better. Leave comments in the section down below or drop me an email at Your feedback matters. Dzięki! Merci beaucoup!



Jacek Laskowski

Freelance Data Engineer | #ApacheSpark #DeltaLake #Databricks #ApacheKafka #KafkaStreams | Java Champion | @theASF | #DatabricksBeacons