Talks & speakers

Vladimir Dementyev's speaker picture

Vladimir Dementyev

Vladimir is a mathematician who found his happiness in programming Ruby and Erlang, contributing to open source and being an Evil Martian. Author of AnyCable, TestProf, Ruby Next and many yet unknown ukulele melodies.

Profiling Ruby tests with Swiss precision

Tests occupy a significant amount of developers’ time. We write them, run locally, and wait for CI builds to complete—the latter can last from a cup of coffee to a good day nap. And unfortunately, such “naps” are pretty common in the Ruby and Rails world.

Luckily, the reasons for slow tests vary greatly between codebases: misconfigured environment, test-unfriendly dependencies, and, of course, factories and database interactions in general.

I like to demonstrate the tools and techniques to help you identify bottlenecks in test suites to help you stay awake.

Isabel Steiner's speaker picture

Isabel Steiner

Isa Steiner started her career as a research Engineer in Swisscom Innovations after her Computer Science studies. In 2008, she joined as an Engineering Director. After spending some years in technical leadership positions, she moved to Swisscom’s Outpost in Silicon Valley before joining as a CTO one year later. After an other year in Product Management at YouTube, she started a as CTO of, followed by her own ventures The Happy Lab, digitizzy, KidsCircle and Rflect. Her passion is to lead x-functional organizations, enable them to develop new products in a lean way and to inspire the next generation of engineers, product managers and leaders.

How to bootstrap your software startup

In 2022, a close friend and former co-worker and myself founded The Happy Lab GmbH and we only had one purpose for the company: A place where happy co-workers develop products to make users happy.

In 6 months we went from exploring the problem space to come up with the first hypotheses a to a platform with recurring revenue by following the principles of lean startup and applying all the techniques and methods we have learned in our 15+ years in product management, engineering and leadership positions. In my talk, I will walk the audience through our bootstrapping steps and learnings.

Ju Liu's speaker picture

Ju Liu

Ju was born in China, moved to Italy as a kid, grew up eating a lot of pasta, and started messing around with computers. He now lives in the UK and has learned to enjoy queueing. He's been writing Ruby for more than 10 years, and now works at Shopify as a Staff Engineer. When he’s not doing that, he’s probably rock climbing.

The Functional Alternative

We'll start with a simple Ruby Kata and solve it together, live, with imperative programming. We'll then fix the many, many, many things we got wrong. Then we'll solve the problem again using patterns from functional programming. You'll leave this talk with a clear and concrete example of why functional programming matters, why immutable code matters, and why it can help you writing bug-free code. The next time you find yourself writing imperative code, you'll think about... the functional alternative.

Abiodun Olowode's speaker picture

Abiodun Olowode

Abiodun Olowode is a software developer at Factorial in Barcelona, who due to her passion for solving problems and building solutions, made the switch to software engineering from Avionics engineering. She is very enthusiastic about sharing her knowledge and breaking down complex technical concepts, via writing. You'll find some of her Ruby articles on the AppSignal and HoneyBadger blogs. In her free time, she enjoys watching movies and documentaries to learn more about the world. She's always up for a new challenge, especially when it involves making the world a better place one line of code at a time.

A Sneak Peak into Ractors!

Are you tired of dealing with race conditions in your Ruby code? Introducing Ractors - an experimental feature designed for parallel execution without thread-safety concerns. But are they really as fast as threads? And are they worth the trouble? In this talk, we'll explore the ins and outs of Ractors, shedding light on how they work and helping you decide if they're right for your project

Harriet Oughton's speaker picture

Harriet Oughton

Harriet is a full-time software developer at Zivio, and a part-time Batch Manager of Le Wagon London's web development bootcamp. Prior to retraining as an engineer, Harriet worked in education for around 10 years, rising to take on some whole-school leadership responsibility. Harriet is also involved in the mighty Women and Non-Binary Rubyist's Network (WNB.rb), and is planning on launching a mentorship program in collaboration with them to improve confidence issues raised by the community. Away from the computer screen, Harriet is a proud member of the UK's nerdiest rock band, 'Depeche Code', comprised entirely of software engineers. Follow her work (and occasional band content!) at @chordsandcode on Twitter or on LinkedIn (Harriet Oughton).

Postcards From An Early-Career Developer's First Months: Recognising the Struggles and the Joys

In the fast-paced learning environment of software development, it can be hard for more established developers to remember the experience of someone finding their feet in their first software role. This talk aims to remind most of us of the common things that new developers learn, grapple with and celebrate in the first few months on the job, and for the juniors themselves, to expose how common these struggles are (and hopefully provide some pointers along the way!).

Cristian Planas' speaker picture

Cristian Planas

Anatoly Mikhaylov's speaker picture

Anatoly Mikhaylov

About Cristian

I am a software engineer that has been working primarily with Rails since the release of Rails 3, more than 10 years ago. Performance optimization has been an obsession for me since I founded my first start-up as a solo engineer in 2012. Currently, I am a group tech lead and senior staff engineer at Zendesk, where I focus on performance optimization.

About Anatoly

I live in Dublin, Ireland. I'm Performance and Reliability engineer with over 15 years of experience. I'm part of Capacity and Performance team at Zendesk where I'm responsible for capacity management, infrastructure rightsizing, building sophisticated observability, running performance workshops and ensuring large complex system is up and running reliably and cost efficiently. My team plays key role in incidents response to performance and capacity related outages. I also contribute to Zendesk Engineering and Nginx blogs, publish with USENIX Login magazine and present Zendesk at several tech conferences and online webinars.

A Rails performance guidebook: from 0 to 1B requests/day

Building a feature is not good enough anymore: all your work won't be of use if it's not performant enough. So how to improve performance? After all, performance is not an easy discipline to master: all slow applications are slow in their own way, meaning that there is no silver bullet for these kinds of problems.

In this presentation, we will guide you across patterns, strategies, and little tricks to improve performance. We will do that by sharing real stories of our daily experience facing and solving real performance issues in an application that daily serves billions of requests per day.

Karen Jex' speaker picture

Karen Jex

Karen was a database administrator for over 20 years and was once described as “quite personable for a DBA”, which she decided to take as a compliment. Karen is now a Solutions Architect, helping customers to design and implement their database systems. Outside of the world of databases, Karen loves cycling, mountain biking, skiing and spending time with her family in the mountains where she lives, and she’s doing a part-time PhD in Computer Science, related to Open Data.

How to Keep your Database Happy

You don't want to spend too much time looking after your database; you've got better things to do with your time, but you do want your database to run smoothly and perform well. Fortunately, there are a few simple things that you can do to make sure your database ticks along nicely in the background.

I've put together my top 5 tips, based on things that have been useful to me as a DBA. The focus will be on Postgres, but most of the tips are also relevant to other databases. These are things you can put in place, without too much effort, to make sure your database works well.

Raia's speaker picture


Since 2015, Raia has been creating original live coded compositions in Sonic Pi with vocal layering. A founding member of Algorave India, much of their live coding is shared through workshops and live shows, supported by zkm, Goethe institute and the Canada Council for Arts. Being autodidactic in music and coding, xe brings a unique outlook to live coding production. The resulting effects are lyrical music, enveloped by code, with the potential to connect.

Anatomy of a Sonic Pi Song

Have you ever considered what makes a "good" song? Maybe it's a sweet melody, or the beat that keeps you pushing through to the end of a workout. Whatever the use case, Ruby-based Sonic Pi can synthesize it. Raia guides participants through coding a range of song components. Together, we'll build a band of live loops including: rhythm sections, melody, chord progressions and audio embellishments. We'll build a song that can be mixed and modified at will and in the process, learn some key elements of what makes Sonic Pi "sing.”