Konstantin Kustau

CEO

Berlin, Germany9 yrs 7 mos experience

AI EnabledAI ML Practitioner

Key Highlights

10+ years of mobile development experience.
Expert in Kotlin Multiplatform for cross-platform solutions.
Proven track record of reducing user churn and bugs.

Stackforce AI infers this person is a Mobile Architect specializing in Fintech and EdTech with extensive experience in Android development.

Contact

konstantin.kustau@gmail.com LinkedIn

Skills

Core Skills

Android DevelopmentArchitecture

Other Skills

Kotlin MultiplatformModel-view-viewmodel (MVVM)ScrumRoomMentoringObject-Oriented Programming (OOP)CoroutinesFirebaseNavigation ComponentRetrofitArtificial Intelligence (AI)JiraAndroid SDKDesign PatternsKotlin Flow

About

I help mobile teams ship faster, cut costs, and scale to millions of users Most companies hit the same wall: their Android app grew organically, architecture became a mess, features take months instead of weeks, and maintaining separate iOS and Android codebases drains the budget I fix that. 🔧 What I Do: - Mobile architecture design & refactoring (Clean Architecture, modularization) - Kotlin Multiplatform (KMP) migration - one codebase, two platforms, 30-40% cost savings - Performance optimization (load time, memory, build speed) - Architecture audits - find bottlenecks before they become disasters 📊 Results from past projects: - Reduced user churn by 6% in a 40M+ user banking app (retention initiative) - Increased product revenue by 11% and attracted 50,000 new users after UX relaunch - Grew company's user base by 16% in Asia-Pacific within 3 months after app launch - Accelerated feature development by 18% through Clean Architecture adoption - Reduced production bugs by 19% with automated testing strategy 🏆 Background: 10+ years in mobile. 17 commercial projects across Android, iOS, and web. Apps used by millions. Worked with teams from startups to 2,500+ employee enterprises. Currently exploring on-device AI integration for mobile apps. 📞 Let's talk: Book a discovery call - link in Featured section

Experience

9 yrs 7 mos

Total Experience

1 yr 7 mos

Average Tenure

Current Experience

Independent consultant (wyoming c-corp)

Mobile Architect

Mar 2025 – Present · 1 yr 2 mos · United States · Remote

Mobile architecture consulting for product companies scaling their Android apps and migrating to cross-platform
Current engagement:
Retention-focused Android initiatives in a 40M+ user banking app - driving technical execution across product, analytics, and platform teams
Architecture and code reviews across shared Android banking codebase; mentoring engineers and supporting cross-team technical decisions
Delivered features contributing to a 6% reduction in user churn across the retail mobile segment
What I help teams with:
Architecture design & refactoring (Clean Architecture, modularization)
Kotlin Multiplatform (KMP) migration - one codebase, two platforms, 30-40% cost savings
Performance optimization (30-50% load time reduction, 20-30% memory improvement)
Architecture audits - find bottlenecks before they become disasters

Android DevelopmentKotlin MultiplatformArchitecture

Gurusforge

Android Staff Engineer / Tech Lead

Nov 2023 – Mar 2025 · 1 yr 4 mos · United States · Remote

Led the technical co-founding of the online education startup from scratch, taking full responsibility for all technical aspects, including architecture, development, and technical strategy.
Led the development of an Android app for the educational platform, mentoring the team in building the app from scratch. Delivered the project to the pre-release stage 17% faster than the initial documented estimate.
Configured an online education platform from scratch, setting up the system for GurusForge, client-experts, and students, which established the technical infrastructure for the startup's services.
Technically launched 3 courses for clients, with a total of about 1,800 students across all courses, generating revenue for the startup and its client-experts.
Implemented SCRUM processes, resulting in a 24% increase in team efficiency, including faster decision-making.
Projects:
GurusForge / USA / Online education.

Model-view-viewmodel (MVVM)ScrumRoomMentoringObject-Oriented Programming (OOP)Architecture+31

Cartrack

Android Engineer (Staff-level responsibilities)

Apr 2021 – Nov 2023 · 2 yrs 7 mos · Portugal · Remote

Worked in an international company with over 2,500 employees globally, contributing to both internal commercial products and outsourcing projects.
Introduced and developed the Clean Architecture approach within the mobile development department. This accelerated the development of new features and reduced technical debt.
Contributed to 4 key in-house and outsourced projects at various stages.
Developed and introduced the automated testing approach for Android apps. This reduced the number of bugs in production by 19% after the release of new major features.
Technically led one large project from scratch, from architecture to team coordination, taking into account business requirements, my contribution has significantly strengthened the company's position in Asia Pacific.
Communicated with top management to align business requirements, successfully leading project delivery.
Coordinated team members at various stages of development to ensure project milestones.
Projects:
Involved in 4 NDA-protected projects at various stages
Regions: EU, Asia Pacific, South Africa
Industries: Vehicle Software, ERP

Model-view-viewmodel (MVVM)ModularizationScrumKanbanRoomEspresso+37

Shelfy.io

Android Senior Software Engineer

Oct 2019 – Mar 2021 · 1 yr 5 mos · Israel · Remote

Worked in an e-commerce startup with a user base of over 10 million users.
Fixed all critical bugs within the first month, reducing user complaints by 28% and improving app store ratings.
Increased product’s income by 11% shortly after launching a new UX. This improvement also contributed to
attracting over 50,000 new users.
Developed and released 7 new features, enhancing functionality and user engagement.
Conducted regular code reviews, implemented refactoring, and improved code quality, leading to a 22% increase
in team productivity.
Improved app performance, reducing load time by 16% through code optimization.
Projects:
Shelfy / Israel / E-commerce (10M+ users)

ReactiveXModel-view-viewmodel (MVVM)ModularizationScrumRoomEspresso+37

Sciencesoft

Android Software Engineer

Jun 2018 – Sep 2019 · 1 yr 3 mos · Minsk, Abu Dhabi · On-site

Worked in a large outsourcing company, involved in international projects across various industries.
Contributed to 4 outsourcing projects for clients from different countries.
Designed a reliable architecture, reducing Android app development time from 5 to 3 months.
Delivered public speeches on emerging technologies, sharing knowledge and expertise within the company.
Projects:
Project is protected by a Non-Disclosure Agreement (NDA) / UAE / Secure Mobile Technology
LatticePro / USA / Healthcare
Lixar / Canada / Healthcare
SINAM / Belarus / Banking

ReactiveXModel-view-viewmodel (MVVM)ScrumKanbanPayment integrationRoom+41

Vironit

Software Engineer

Jun 2017 – Jun 2018 · 1 yr · Minsk · On-site

Enhanced tech and soft skills in working with international teams and mentoring other developers.
Contributed to 3 different international projects for clients from various countries.
Conducted project estimations for large-scale projects across various industries and clients.
Projects:
Yota / Russia / Mobile operator app (10M+ users)
Pluggd / Canada / Job Marketplace
WorkshopChat / USA / Automotive

ReactiveXKanbanPayment integrationRealm DatabaseObject-Oriented Programming (OOP)Architecture+33

Golden software

Software Engineer

Jun 2015 – Jun 2017 · 2 yrs · Minsk · On-site

Improved technical skills while contributing to bug fixing and developing new features.
Contributed to the development of 3 product-based system ERP projects as a junior specialist.
Projects:
GdmnTradeAgent / Belarus / ERP
GdmnSkeleton / Belarus / ERP
GedeminSalary / Belarus / ERP

ReactNativeRealm DatabaseObject-Oriented Programming (OOP)ArchitectureFirebaseRetrofit+20