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Hello, I'm

Justyna Rosielewska

Senior Android Developer

An Android developer with over nine years’ of experience who is passionate about elegant apps with high quality code that help people in daily life.

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About me

Why Hire Me?

Working on engaging Android applications with start-ups, mid-sized and large organisations, and having field-tested experience as a lead developer, working closely with Business Analysts, Product Owners and Quality Assurance alike to deliver innovative solutions and complex features. Working as a Tech Lead for the UK's leading provider of digital hospitality solutions and developing leading marketplaces apps with millions of users (e.g. for JD Wetherspoons and Greene King). My skills are:

Java

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Kotlin

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Jetpack Compose

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Coroutines, Flow

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Room

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MVVM, MVP

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Git

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Gradle

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Retrofit

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Braintree

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Worldpay

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Firebase

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Robolectric

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Espresso

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Service

I'm Good At

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Android Development

Creating complex, user friendly apps based on customer demands and from personal design. Developing clean, high quality and scalable code.

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Business Analysis

Converting customer needs into technical requirements and user stories. Producing technical diagrams for app integrations.

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UX/UI Design

Designing and implementing beautiful apps, using material design and newest trends in modern apps.

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On Time Delivery

Delivering projects on time based on precise estimation and detailed user stories.

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Problem Solving

Solving complex issues based on my experience and research. Finding best technologies to handle any challenge.

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Web Development

Creating simple, elegant and professional websites for small businesses and sole traders.

Experience

Work Experience

01

Senior Android Developer

Director

January 2025 - now

Anjuros Development

Independent contractor, working on personal apps, designed and created from scratch in collaboration with my clients' specific requirements.

Independent contractor, working on personal apps, designed and created from scratch in collaboration with my clients' specific requirements.

01

Senior Android Developer

Director

January 2025 - now

Anjuros Development

02

Tech Lead

January 2024 - December 2024

Zonal Retail Data Systems Limited

In my role of Tech Lead I continued to work on our flagship Android application and routinely collaborated with our Business Analyst to create User Stories based upon our customer demand pipeline. I was responsible for producing technical diagrams of our app's integration into other systems to better prepare the team for upcoming work schedules and to ensure compliance with our internal security team. I further engaged in meetings between Senior Product Owners in order to demonstrate proposed solutions of upcoming features. More recently I had been called upon to participate in customer requested security audits related to our integration with payment providers, as well as our development practices and security posture.

In my role of Tech Lead I continued to work on our flagship Android application and routinely collaborated with our Business Analyst to create User Stories based upon our customer demand pipeline. I was responsible for producing technical diagrams of our app's integration into other systems to better prepare the team for upcoming work schedules and to ensure compliance with our internal security team. I further engaged in meetings between Senior Product Owners in order to demonstrate proposed solutions of upcoming features. More recently I had been called upon to participate in customer requested security audits related to our integration with payment providers, as well as our development practices and security posture.

02

Tech Lead

January 2024 - December 2024

Zonal Retail Data Systems Limited

03

Senior Android Developer

June 2022 - December 2023

Zonal Retail Data Systems Limited

As a Senior Android Developer my additional responsibilities were to onboard new developers for the Android and iOS teams and I also actively participated in the recruitment process. In the course of this role I added over 70% of test automation coverage to the app. I was instrumental in leading the technical debt meetings for the team as well as being an active member of design sessions, advising on the pros and cons of certain technical approaches to specific problem domains. During this role I was responsible for refactoring our app's integration with the Braintree payment provider and further integrated the app with Worldpay. I also lead a project for adding a unified user journey, which leveraged deeplinks to specific parts of the app to facilitate an enhanced user experience.

As a Senior Android Developer my additional responsibilities were to onboard new developers for the Android and iOS teams and I also actively participated in the recruitment process. In the course of this role I added over 70% of test automation coverage to the app. I was instrumental in leading the technical debt meetings for the team as well as being an active member of design sessions, advising on the pros and cons of certain technical approaches to specific problem domains. During this role I was responsible for refactoring our app's integration with the Braintree payment provider and further integrated the app with Worldpay. I also lead a project for adding a unified user journey, which leveraged deeplinks to specific parts of the app to facilitate an enhanced user experience.

03

Senior Android Developer

June 2022 - December 2023

Zonal Retail Data Systems Limited

04

Android Developer

July 2018 - May 2022

Zonal Retail Data Systems Limited

As an Android Developer I was working with a legacy code base containing multiple complex features. I was responsible for constantly improving the app by adding new functionality and feature sets and also refactoring into Kotlin.

As an Android Developer I was working with a legacy code base containing multiple complex features. I was responsible for constantly improving the app by adding new functionality and feature sets and also refactoring into Kotlin.

04

Android Developer

July 2018 - May 2022

Zonal Retail Data Systems Limited

05

Android Developer

February 2016 - March 2018

notiOne

In this role I was creating an app based on Bluetooth technology and beacon hardware devices. I fully integrated the app with several map libraries - Google Maps, MapBox and OpenStreetMap. I was participating and leading meetings with different teams within the business such as Server, iOS, Graphics and Marketing. The company was a startup, which was spun out from the parent company and I was the first Android developer recruited for the project.

In this role I was creating an app based on Bluetooth technology and beacon hardware devices. I fully integrated the app with several map libraries - Google Maps, MapBox and OpenStreetMap. I was participating and leading meetings with different teams within the business such as Server, iOS, Graphics and Marketing. The company was a startup, which was spun out from the parent company and I was the first Android developer recruited for the project.

05

Android Developer

February 2016 - March 2018

notiOne

06

IT Specialist

December 2015 - January 2016

GSK

Configuring and improving secure messaging channels to facilitate communications between healthcare providers.

Configuring and improving secure messaging channels to facilitate communications between healthcare providers.

06

IT Specialist

December 2015 - January 2016

GSK

07

Android Developer

July 2015 - September 2015

Inqbarna

Internship within an Erasmus program, integrating an app with the Facebook SDK and adding in-app video and recording.

Internship within an Erasmus program, integrating an app with the Facebook SDK and adding in-app video and recording.

07

Android Developer

July 2015 - September 2015

Inqbarna

08

C++ Developer

December 2013 - April 2014

In-Software Company

Remote developer position during my studies for a German employer offering general software solutions.

Remote developer position during my studies for a German employer offering general software solutions.

08

C++ Developer

December 2013 - April 2014

In-Software Company

09

C# Developer

June 2013 - July 2013

Kimball Electronics

Contributing code to a logistics solution for medical components.

Contributing code to a logistics solution for medical components.

09

C# Developer

June 2013 - July 2013

Kimball Electronics

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Completed Projects

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Active Projects

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Companies

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