Mangirdas Kazlauskas

Mangirdas Kazlauskas

GDE Dart & Flutter | Mobile Tech Lead @Billo

Kaunas, Lithuania

An experienced product-centric software engineer with a passion for learning and sharing knowledge. As a Google Developer Expert for Flutter & Dart technologies, I excel at building cross-platform apps with Flutter, and I love teaching others what I know. In my free time, I enjoy creating educational content, or just being outside and playing disc golf.

Area of Expertise

  • Information & Communications Technology


  • Flutter
  • Dart
  • Mobile Development
  • Software Engineering
  • Web Development
  • Product Development
  • Mobile Apps
  • Mobile
  • Cross-platform

Make smarter decisions faster with Firebase Remote Config

Firebase Remote Config is a powerful tool that allows you to change the behaviour and appearance of your app without requiring users to download an app update. This means that you can experiment with new features and changes, and see how they impact your users' behaviour in real-time.

In this talk, we will discuss how to use Firebase Remote Config to make smarter decisions faster. We will cover topics such as:

- How to set up Firebase Remote Config
- How to create and manage remote config parameters
- How to test and deploy remote config changes
- How to measure the impact of remote config changes

We will also share some real-world examples of how Firebase Remote Config has been used to improve the performance and user experience of apps.

By the end of this talk, you will understand how to use Firebase Remote Config to make smarter decisions faster and improve the quality of your app.

Entering the Realm of Reactive and Offline-First Flutter Apps

In today's mobile app world, users demand fast, responsive, and reliable apps, even when they are offline. Therefore, developers spend tremendous effort on app architectures, supporting offline-first and reactive features, like offline data synchronisation or real-time data and UI updates. However, that was never an easy task.

In early February, the MongoDB team announced the general availability of Realm for Dart and Flutter. Realm is a database designed with the mobile environment in mind - fast, lightweight, and optimised for constraints like computing, memory, bandwidth, and battery usage. With Realm, developers can now create performant, reactive, and offline-first Flutter apps with ease.

In this talk, we will extend the existing Flutter app with reactive features using Realm and will make sure to provide the best possible offline app experience.

Key takeaways:
- The benefits of creating offline-first and reactive apps;
- The advantages of using Realm as a database in Flutter;
- How to add Realm to the new or already existing Flutter app;
- Using Realm for reactive data synchronisation;
- App architecture and design considerations for offline access.

Control your Flutter application on the fly with Firebase Remote Config

Real-time updates, A/B testing, app personalisation - what if I told you that you could enable these powerful features in your Flutter application with minimal development effort and without any costs? Firebase Remote Config is a free service that enables changing the behaviour of an app remotely without publishing an app update. In this talk, I will cover multiple real-world use cases where Firebase Remote Config could help you while building Flutter apps.

The talk will revolve around an example app that will be gradually extended with multiple Firebase Remote Config features. Specific use cases covered in the talk:
1) App configuration values;
2) Notifying users about a new app version;
3) Feature toggling (enabling/disabling features on the fly, staged rollout, etc.);
4) App personalisation (using different config values based on conditions - platform, language, region, date/time, etc.);
5) A/B testing;
6) And more!

Talk's rating based on the audience feedback:
Fluttercon 2023 (55 responses) - 4.8 / 5

Observation-based product development using Flutter

Any Flutter developer knows how great this SDK is at creating beautiful, performant, and portable apps. Usually, we do not want just to create an app - we want to build THE product. We want to create something that will be used by our users daily, bringing them joy and making their life easier. Thus, it's crucial to keep a finger on the pulse of the users' behaviour, understand their struggles and needs, and later make observation-based decisions to improve our products. In this talk, I will share some real-world tips and tricks used in developing products that users love and care about.

This talk covers three main app observation strategies:
1) App monitoring - logs, error & crash reports, performance metrics;
2) Product metrics - app metrics and analytics;
3) UX - internal and external user feedback.

Let Me Introduce You to Flutter

Flutter is Google's UI toolkit for building beautiful, natively compiled applications for mobile, web, desktop, and embedded devices from a single codebase. Over 700,000 Flutter apps are published to Google Play and Apple App stores to date, including products created by world-leading companies such as Google, Amazon, Alibaba, eBay, and BMW. According to the JetBrains 2021 State of Developer Ecosystem survey, Flutter is the most popular cross-platform framework in the world. Native performance, a single codebase for different platforms, sound null-safe development, and an increasing number of tools and integrations - that's only a fraction of what Flutter offers to every developer. I think it is time for me to introduce you to Flutter!

Design Patterns toolbox: (not so) obvious patterns for Flutter

Overview of some OOP Design Patterns and their pure implementation in Dart as well as seeing them in action by investigating the example app.

Originally presented during the "DartUP 2020" conference.
Presentation and example app: https://github.com/mkobuolys/dartupify-dartup2020

Make the code work for you: Flutter Code Generation

Every programmer's dream is constantly building new features and seeing how the project grows. However, there is nothing worse than writing a lot of boilerplate code just before even start implementing those features. In this talk, you will learn about Flutter code generation tools and various tips on how to avoid implementing boilerplate code and focus on your next-gen project.

Originally presented during the "Flutter Global Summit'21" conference.
Presentation and example app: https://github.com/mkobuolys/flutter-code-generation

Flutter Firebase Festival

September 2023 Prague, Czechia

Fluttercon 2023

July 2023 Berlin, Germany

plDroid 2023

Let me introduce you to Flutter

May 2023 Warsaw, Poland

Appdevcon / Endpointcon 2023

May 2023 Amsterdam, Netherlands

Cross feat. Flutter

Make the code work for you:Flutter Code Generation

March 2023 Kraków, Poland

Flutter Forward Extended Vilnius

What's new in Flutter 3.7 and Dart 3.0

February 2023 Vilnius, Lithuania

MDL Meetup #15

Observation-based product development using Flutter

November 2022 Riga, Latvia

droidcon London 2022

October 2022 London, United Kingdom

Flutter Festival London 2022

March 2022 London, United Kingdom

Mangirdas Kazlauskas

GDE Dart & Flutter | Mobile Tech Lead @Billo

Kaunas, Lithuania