In May 20016 it’s been 2 years since I’ve started to work for SoftwareMill. And it was a huge pleasure to work for a such software engineer friendly company. That is why it’s so hard to say goodbye.


SML (internal shortcut for SoftwareMill) was 21 people when I joined and raised up to 40 now. Projects base is growing, more people and friends are joining – it’s definitely a great place to be! SML stands out because of it’s trust to employees, as one you get information about financial condition of company and all it’s costs. SML was always reliable for me.

I was far more excited about the culture of SoftwareMill (self organising teams a’la Spotify) and autonomy I got. If someone asks me I highly recommend SoftwareMill company for doing business with. I’ve learnt more about leading the project and a lot of tech details like functional, async and non-blocking style of programming in Scala. And I hope the company is satisfied with my work and open source contribution to bootzooka. I’ll miss friends from SML and hopefully stay in touch with them and meet on some dev crowd conferences.

SML is almost perfect, but there are companies with also interesting challenges that pays better.

My friends created such a company, it’s called ValueStream which I’ll join in June. And ValueStream is hiring so please contact me in case you are interested ;)

On picture: Me with t-shirt I got from SML for my birthday, saying: Kowalski what are the options?


WebSummit 2015 is a tech conference for geeks, this time it was organized in Dublin, Ireland.

The well spotted summary of WebSummit 2015 edition might found here:

I encourage you to read it – it’s only 7 minutes long.

TL;DR from that article: WebSummit speakers are not attending to wow developers and creatives, they’re here to impress business owners. It’s that simple. Web Summit might be great if you’re a startup and you’re looking for investment.

IMG_20151105_090608I’m software developer experienced in writing webapps on jvm. What, a guy like me, might be looking for at such a conference – touted as `Davos for geeks`? Maybe some leads (except a few interesting talks – Bryan Lilies, Alistair Crolls). Conference was huge. I usually attend developers conferences up to 1k of people, this one was massive 30k attendees. I had an amazing time in Dublin with my teammates, every evening we joined night summit to make a new friendships. As a neophyte salesman you wish to talk to each and get know every single story but it’s simply impossible and unfortunately you have to live with that awareness. After a first few talks you got an impression that you are all around amazing talents with amazing ideas and products.

I’ve met a guy coming here for 1mln $ for his ultra fast(~1h for complete app) mobile apps drag&drop building framework. Of course I have seen a few of such a wonder-tools before and after very promising and beautiful beginning of those, users wanted something custom. I really believe the world needs more of those. One day it will happen and all software developers would be fired ;)

I remember a cool guy from Australia living with his wife in Chile and having a social startup that helped neighbours organize their kids a schools transport with their private cars. I suppose the are no buses or are expensive or you can’t trust anyone, anyway it solves nicely a serious issue.

IMG_20151105_085214I was impressed by guys with I saw some great pitch talk from making me wanna throw my money into them. I want to order to get call to my smartphone from people standing in front of my doors. But as I don’t practise expensive shopping trips to Mediolan or London I can only recommend to some a for planing that routes and as I don’t have a dog I won’t be a user of one of many dogs social services.

I’ve gathered some business cards from distinct companies, I’ve also exchanged some electronic ones. I talked to some potentially interested in our services personalities. I had one inquiry about a project estimates and one about our rates… and that’s all. No serious lead worth to put in our highrise. At the conference I met nice guys from another polish company with comparable luck of turning WebSummit leads into sales ;)

I was excited to see David Heinemeier Hansson and Raffi Krikorian live but both didn’t make it to come at the end. David has justified his absence and published a great – common sense – article that should be familiar for fans of “Rework” and “Getting Real”.

Posted is 100% Free Roche Software Conference. Invited speaker guests were: Dr. Venkat Subramaniam, Greg Young, Dino Esposito.

Adam Waltman from Roch Poland gave an interesting welcome speech, I could comprehend about internal IT Roche structure, and that price of sequencing DNA dropped from 100 mln $ since 2001 to 1k $ now (2015) and continuing that reduction in price. Basically sequenced DNA is a 3 GB file. Scientists do parental test comparing DNA of parent and a child. Except that they can give more precise predictions to inclinations of illnesses like cardiovascular diseases and cancer. Would you like to give this information to insurance companies for free?

In Dr. Venkat’s talk “The art of simplicity”, he pointed too much complexity around in our industry out. It’s hard not to agree with him. Dr. Venkat. He cited a talk of two interns after completing internship: “Dude, that company was awesome, I didn’t understand any line of code there”. What obviously is bad, bad practise. How expensive is that code to maintain in terms of time and recruitment (only the brave ones)? How fast can you find/fix a bug in that code? How big is bus factor? How big would rotation be in dev/ops teams then? Presentation included nice quotes:

“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.”

― Antoine de Saint-Exupéry, Airman’s Odyssey


“If you can’t explain something to a first year student, then you haven’t really understood it.”

― Richard Feynman

In “Core Software Design Principles” with a bunch of live coded examples Dr. Venkat was convincing people to functional programming. I love lambdas whether it’s java8, scala, groovy, javascript. I’ve seen that talk previously or cope with the essence is my daily routine which I love so listening to that increased my ego, that I’m on right path ;)

Unfortunately Greg Young couldn’t make it. That day I thought he had a hangover but after two days when I got stomach flu (what was awful) I imagined him suffering exactly as I, so I forgive the absence. In place of Greg, Dr. Venkat gave another talk about javascript (Dino gave extra talk as well). His talks and the style of them are worth see and pleasant to listen to. He started with var directive – not block scope, hoisting, new const and let from es6 and more of other unconscious traits of js.

Dino and Greg were speakers I haven’t seen live before. I discovered Dino Esposito this time. He is a great speaker with good audience connection, I mean his talk is interesting, dynamic, with lot of gestures (Italian style;) and addictive.

The first talk “The impact of UX on software architecture and design” included an example of UX misunderstanding between business and a software developer. Business may verbalize it’s main aim, desire or request but there are many ways of implementation that idea. Dino received request to write match of tennis player name with his drawn number. The first version of that application was the most trivial (and I’m sure that everyone would deliver exactly same solution) – two input boxes and submit button. Client responded that it was too slow(?!). And final app had already provided a list of player names and the grid with numbers and placeholders for names, the user had only to move names to grid cells. That was completely different UX then that Dino imagined after reading the spec first time.

The second was no less interesting “Pros and Cons of Responsive Web Design”, where Dino revealed that responsive apps send same amount of data to mobile devices as to desktop. Mobile friendly frameworks with css only hide elements on mobile. It’s no problem in Poland where you have LTE broadband network in major cities but may be a problem for the external regions or countries that don’t have LTE ( Surprisingly, I was in Dublin and had no LTE, maybe that was restricted for roaming connections – I dunno). Even though, it’s a challenge for webapp industry in following years to decrease that mobile traffic, bandwidth and at the end costs. Dino also reminded us why Google created angularjs… simply for gmail. Rendering all that stuff on server side required a lot of server power and electricity. Client side rendering helped them to make significant savings. Dino also talked about amazing service called – proxy for resized images. You link your images through proxy and it serves smaller resolution image to mobile and full to desktop. That’s great!

The venue (sound system, recording) and catering were professionally prepared, I think there was something between 200-300 attendees. This was Roche hosted event so there was hiring announcement – what was perfectly fine. That’s definitely the way to go for other companies seeking developers – invite professional speakers, fund catering, receive resumes ;) We, SoftwareMill are organising Scalar conference and are constantly looking for scala developers as well. 


This year I’ve attended Principles of Reactive Programming course. It wasn’t easy one, at least for me.

I mean, first two weeks driven by Martin were clear and straightforward. Even first Erik’s week about Future was approachable. The rest -rxScala with it’s Observables and actor model with Akka was rather hard and required a lot of work. My conclusion: akka isn’t easy concept (contrary to all akka guides saying it is) maybe it’s easier to debug when things go bad comparing to standard java locking/synchronisation model but for designing it requires a lot of time and hard work to acquire that way of thinking.
Except videos on course pages I red other helpful materials like:

  1. Learning Concurrent Programming in Scala book by Aleksandar Prokopec
  2. The Neophyte’s Guide to Scala

and two cheet sheets dedicated for this course

  1. by sjuvekar
  2. by dnvriend

And good akka tutorials

  1. Concurrency and Fault Tolerance Made Easy: An Akka Tutorial with Examples by Diego Castorina
  2. Reactive twitter app with akka by Jan Machacek
  3. Implementing the Reactive Manifesto with Akka by Adam Warski – video

Maybe someday that materials would help you.