Poznan University of Technology

Independent Android Consultant & Trainer

London, England, United Kingdom

Independent Android software consultant and trainer. Usual assignments vary from joining a project early on and building its solid foundations to reinforcing a team at a time-critical stage, getting up to speed quickly, helping with delivery of features and fixing usually the trickiest bugs. Consulting services include: feasibility study, prototyping, advising on features, effort estimation, code-reviews, code quality assessment, recruitment/technical screening/interviewing, bug fixing/investigation. Always keeping the saw sharp, investing time in training.

Self-employed

Android Developer

Engaged to help with increased workload due to replatforming effort (REST → GraphQL). Proposed codebase improvements that have been accepted by the team and implemented. Keywords: TDD, MVVM/MVI, Rx, Kotlin, remote pair-programming, Apollo GraphQL, image processing.

Moonpig

Android Engineer

Delivered a major improvement to a public Android library. Created a facility for writing functional tests that mock the backend. Fixed a few tricky issues and liaised with customers within the process. Came up with significant improvements to the public API design which have been approved by the team and later received very positive feedback from early adopters. Played instrumental role in design and implementation of internal architecture of the SDK. Keywords: Kotlin, functional programming, ReduxKotlin, Koin, Spek, Assertk, MockK, Detekt, Ktlint, Codecov, Java, NaCl (crypto).

Pusher

Android Lib Developer

Engaged further beyond the codebase audit phase to inspire and drive code quality improvements. In an iterative way, refactored a complex feature to serve as the reference implementation of the core clean architecture layers, the domain model and the use-case layers. Introduced dependency injection alongside the infrastructure to use it at interim refactoring steps and to provide test doubles for the UI tests. Established single-source of truth and data immutability for state management. Introduced Kotlin and started the upgrade to Mockito 2 (successfully moving the main modules) to be able to mock Kotlin classes without compromising their design. The refactored feature was unanimously and enthusiastically accepted by the team and agreed to serve as the example to follow. The code structure it presented was easy to reason about and significantly reduced complexity concentration and duplication thanks to its clear responsibility split. Supported the team through code reviews of the most important changes, pairing with individual developers and delivering presentations on topics like dependency injection or improvements in Espresso (UI) tests. Keywords: SOLID OOD principles, Clean Code/Architecture, MVVM, Structure101, Kotlin, Dagger 2,  PCollections, RxJava, Arxan, Mockito 2, BDD.

Yoti Ltd

Android Architect

Carried independent codebase audit focused primarily around the code quality with the aim to provide suggestions of where and how the app’s maintainability can be improved. The app clearly cannot be described as a thin-client but as an app that delivers significant sophisticated logic, around security (keystore, crypto, HMAC, cert pinning), privacy, camera (both photo and video, capture and processing), biometrics, NFC, push messaging, persistence (both prefs and DB). Besides sharing feedback on how to improve code design / architecture to make it easier to understand and reason about, identified a few areas on hardening the app’s security, as well as provided a few suggestions about streamlining the process and enhancing the end product. The team welcomed the findings, finding them intelligible and well reasoned. Was invited to present the high-level overview of the main findings to the top leadership team. Technologies included: RxJava, SQL Brite, Sonargraph, Markdown, Arxan.

Senior Android Analyst

Greenfield FinTech project, 100% Kotlin. Set up the whole technology stack and established the app architecture, that the dev team was happy to follow. Created UI test automation framework that allows to simulate/test different scenarios (with test dependency injection graph) and trained the automation tester to join the dev team extending the use-case test coverage. The app had dozens of different flavours (brands) which required a customised build script and sharing brand specific resources (like texts/colors) with iOS app in a common Git repository. Keywords: Kotlin, Rx, Moshi, Retrofit, Dagger 2 (Android extensions), Clean Architecture, Architecture Components (ViewModel/LiveData), ThreeTenABP, ProGuard, Certificate Pinning, Git submodules, Zeplin, Espresso, TestRule’s for test doubles (fakes/mocks) in DI simulating/verifying complex backend scenarios/interactions.

The App Business (TAB)

Hired to build solid foundations of a greenfield project, designing its architecture, integrating whole tech stack and creating a balanced test pyramid (composed of unit, integration and functional UI tests). Working solo has delivered two sophisticated features and architected the app to handle complex dynamic state changes. Prepared high-level overview decribing the code design and the technology stack for the handover to an agency which was appointed to maintain and develop further the whole product past the incubation phase. Keywords: Reductor (Redux/Flux), Clean Architecture, Dagger 2 (Android extensions), Architecture Components (ViewModel/LiveData), RxJava, Retrofit, AutoValue, ThreeTenABP, Gson, ProGuard, Zeplin, TDD (GUTs), Truth (assertion framework), Espresso, TestRule’s for test doubles (fakes/mocks) in DI simulating/verifying complex backend scenarios/interactions.

BCG Digital Ventures

Assigned to work on a time critical feature of HVAC Thermostat for North American market (US, Canada). Smart thermostats are the most complex and feature-rich devices out of the Hive offering. They constituted the first Hive’s smart home proposition hence the assignment involved quickly getting on the top of the codebase with 5 years of legacy. During organisational changes of moving to cross-platform squads, selected to lead the Environmental Tech squad on the Android side. Driving creation of the strategy of moving towards a more maintainable codebase for the whole Android team. Lead Android dev meetings with a dozen of colleagues, including remote team members, helping finding consensus on clear anti-patterns/tech debt and agreeing on the approach for not escalating them, gradually improving the codebase and making it testable. Introduced Dagger 2 template, establishing 3 Android scopes (Application/Activity/Fragment) and their corresponding injection points. Trained the team and paired with individual colleagues on many occasions around several technologies, design principles or the understanding of how to correctly fix (not hide) bugs. Helped the team to create the culture of productive code reviews that provide value, improving quality and facilitating knowledge sharing. Led creation of Code Review Rules that the team was happy to embrace. Keywords: Clean Architecture, MVP, RxJava, Dagger 2, Fail-Fast (well-applied defensive programming), ConstraintLayout, Evernote JobScheduler backport, AutoValue, Hamcrest, Mockito, TDD (GUTs), InVision, Confluence, Slack, Zoom.

Hive  -  Centrica Connected Home

Senior Android Developer

Reinforced the in-store tablet app team during the handover period from an agency, quickly getting up to speed and taking on the technical leadership for the project. Helped the in-house devs grow, write high quality well-structured maintainable code and establish best software engineering culture and practises. Built Espresso UI automated safety-net and created the framework for also making deep white-box assertions for what's not visible in the UI (e.g. analytics). Quickly and successfully trained and engaged the QA team in automating their manual test scripts and empowered them to easily keep adding regression protection also for white-box aspects (like analytics). Fixed a few tricky long-standing bugs with long history of fix attempts and on a few occasions have managed to find hard to spot regressions early on in the code review phase. Worked with the team on delivering new features, redesigns and improving reporting, tracking, logging and monitoring from within the application. Established closer cooperation, knowledge exchange and code reuse with the consumer app Android team. Technologies used include: RxJava, Dagger 2, OkHttp, JUnit 4 (TDD), Mockito, AssertJ, Hamcrest, Espresso, ViewPager, CoordinatorLayout, NestedScrollView, Jenkins (CI), AutoValue, Logback, SLF4J, RetroLambda, Fabric (Crashlytics, Answers), Appsee, Adobe Analytics, MaaS360 MDM, Zeplin, Slack, TeamViewer.

Argos

Lead Android Developer

Joined a new project at an early stage to help shape the backlog and create the designs (following the material design guidelines). Led effort estimation for the entire project so better business decisions could be made around the scope and planned delivery dates. Conducted the research and made decisions on the main technologies used within the project. Stepped in and came up with a proposition of a RESTful API to help the back end team to deliver a solution which best fulfils the requirements of the product. Later joined by other Android devs worked closely with the rest of the team on building the app which set Lollipop as minimum SDK and utilised some of the newest features introduced in that version of the Android platform. Technologies used include: RecyclerView, VectorDrawable, JobScheduler, DrawerLayout, Toolbar, GridLayout, OrmLite, Retrofit, Espresso, Dagger (Dependency Injection), Jira, Confluence and GitHub.

Worldpay

Was brought on board to help with the delivery of a major enhancement to the concept of the service. Quickly learnt complex codebase and became proficient with the unique domain knowledge. The new version of the app has been successfully delivered within the expected timeframe bringing a significant increase to the user engagement rates. Technologies used include Dagger (Dependency Injection), Retrofit, Gson, Butter Knife, OrmLite, Android Studio, Slack, Trello, Jira and GitHub.

State

Worked on innovative projects for Google. The goal was to perform feasibility studies and build prototypes to test the designed UX. Besides developers the project teams also consisted of designers, producers and the head of technology, with the client actively involved. Worked as the only Android developer, as well as in tandem with another freelancer for 3 weeks. The outcomes were quickly created working prototypes which met the satisfaction of all the stakeholders. Technologies used include: Video/audio processing (Media Codec/Muxer, mp4parser), Volley, View Pager, Android Studio, Gradle, Maven, live wallpapers, NFC, Google Maps (static API), photography, OpenGL (GLWallpaperService, AndEngine), sensors (rotation), Play Store expansion files and Unity integration.

rehabstudio

Brought aboard in the final phase of the project to help with the delivery of crucial features and to fix tricky defects in order to put the app in a shippable state and back on track with the schedule. Discovered and fixed issues with restoring the state of the app when a user returns to it after the app has been removed from the memory by the system (a very important scenario in an Android app lifecycle which is often missed out in development and testing before the first release). Led effort estimation and prioritisation process to create a sensible scope which can be delivered within the set timeframe. Worked closely with another Android developer, a QA and a project manager. Technologies used include: Google Maps Android API v2, Fused Location Provider, Geocoder, Maps on Amazon devices (research), advanced WebView, Android Annotations, Popup Window, KitKat Transitions (animations).

Aimia Inc

Joined a large, distributed team of more than a dozen Android developers with the aim of bringing solid expertise and technical leadership to an eCommerce project. Git was used on a daily basis to its fullest extent with Gerrit employed for code reviews. The feature-rich application the team was working on was originally developed by an external provider and was still in parallel development which has required massive code merges with changes reaching thousands lines of code. The application supports tablets too and uses the most recent features of the Android SDK. Technologies used include: REST XML API, Simple XML Framework, Google Maps Static API, Fragments, ViewPager, AlarmManager, ContentProviders, SQLite DB, AQuery, ABS, EventBus, Push Notifications (GCM, Exact Target), Omniture, Fiddler Proxy.

Accenture

Worked on the NOW TV Android app as part of a team of four Android developers. Contributed to shared Android libraries used by more than a dozen Android developers working for Sky, promoting the code reuse principle across the company. Experience in all of the areas of the application, from writing under the hood networking/caching code to designing UI layouts in XML. Enjoyed the comfort of being protected by Hudson running automated tests and providing fast feedback after every commit (unit tests and Robotium UI tests). The methodology used was Scrum. The team also consisted of four testers that certified what devs claimed is done, is actually done and working. Led technical interviews both over the phone and on-site. On a regular basis represented the team by giving presentations (sprint demos) to executives and colleagues from other teams.

BSkyB

Gave a three days course in September 2013, a two days training for advanced developers in August 2012, and two courses for beginners (0-6 months of Android experience) in summer 2011 which lasted two days also. All the training courses got a very high score in the surveys, in particular assessing skills and knowledge of the trainer at the highest, exceptional level.

Comarch

Android Trainer

Created the Allegro for Android application, through the first year working solo as the only Android developer in the company. Responsible for design, UX and implementation. The app was very successful. It was actively used, bringing a high ratio of conversions. Other numbers which proofs its success are very high marks from its users on Android Market, with the average of about 4.5 out of 5 (where 4 means “above average” and 5 means “excellent”) – with non-excellent marks mostly because of missing features in the current version. And the last but not least, Allegro for Android is very stable, except some minor ones, there were no bugs found after every release during the time when I was the only one person responsible for its development. After the Android team was constituted worked as a lead Android developer. Besides Allegro created also its versions for other countries (Molotok and Aukro) which were different not only in texts but even in some logical aspects. Co-created the Ceneo for Android application, leading extraction of common code to libraries.

Allegro Group

Android Software Engineer

A summer, paid internship, during which I created Community Traffic. My responsibility was to design and implement a very efficient algorithm capable of processing huge amounts of constantly incoming data (issues connected with database systems performance, technologies: Java, MySQL). Project ended with a total success, users and my internship mentor PhD, Dr. Habil Andrzej Jaszkiewicz were very pleased with the way it works. I received the proposition of further employment but mainly due to the fact that studies were the most important for me, I did not accept this proposition. My code is still successfully used and the Community Traffic is the biggest hit out of the NaviExpert features – available only in the most expensive premium subscription.

Marek Urbaniak

Marek Urbaniak