Build Stuff'15 Lithuania

How to keep a real-time, low-latency and high-stakes system up and running and well-monitored? how to investigate failure cases as they happen? and how to even know something is wrong before it's too late? With logs of course. Lots of them. And then some cool stack to do stuff with it.

Forter is a company with a Decision-as-a-Service product that deals with many e-commerce transactions in real time and answers a simple but hard question: "is this a fraud attempt or not?". And if we were wrong, we pay.

In this talk I will show how we are using various technologies to power our service and keep it high-available and well under control. Among the technologies I will discuss are Apache Storm, Node.js, Riemann (state machines in Clojure, yay!), collectd, D3.js and of course the ELK stack (and beats!). Some integrations which will be mentioned include PagerDuty, Slack, Jenkings and GitHub.

The new facilities in Java 8 is about the change the way we write code. Our code will become more expressive and concise. But, exactly how? In this presentation we will take several common Java code examples, discuss the core idea expressed in code, and transform that code to use the facilities in Java 8. Watch and interact as you see Java code go through a weight loss program right in front of your eyes.

Transitioning from OOP to functional style can be quite challenging, not least because OO programmers are used to thinking in nouns. Programming languages that use functions as primary means of abstraction force one to:

- design things in terms of verbs,
- find new ways of doing composition,
- rediscover polymorphism in a different light.

Fear not! What you have learned about good OO design can be applied to FP, in obvious and weird ways. Code examples will be presented in Clojure.

How can big data or highly responsive applications scale to the increasing demands for speed and short response time? Adding more servers to the cluster is not the answer. The smartness comes from being lazy as laziness can translate to efficiency and scalability. In this presentation we will learn about what lazy evaluation is, explore some data structures and APIs that promote lazy execution, and tie it back into scalability and efficiency.

Session is about mutation testing, why and when you should mutate your code. What benefits comes by mutating your code. Simply test your own tests. It's very helpful tool with TDD where you are exposed to a lot of wrong assumptions and simple syntactic errors that can propagate other errors.