Ivan Ts., Lead Kotlin /Java Engineer
B2 (Upper-Intermediate) English
Senior (5-10 years)
Lviv,
Ukraine
UTC+02:00
Summary
Ivan is a Lead Kotlin/Java Engineer with solid experience in backend and Android development. He builds reliable and maintainable applications, works well with cross-functional teams, and enjoys improving codebases and system architecture. Ivan is comfortable mentoring others and contributing to both mobile and backend projects, making sure they run smoothly and efficiently.
- Software Engineer with 5+ years of experience in developing Android and backend solutions in the healthcare, fitness, and automotive industries;
- Strong Skills with Kotlin, Java, and TypeScript, creating Android applications on Jetpack Compose, Firebase, Android SDK, KMM, as well as backend solutions on Spring Boot (and basic experience with Node.js / React for integrations and prototypes);
- Experienced with AWS (Serverless, Lambda, S3, API Gateway) and GCP, builds cloud infrastructure, and is undergoing Google Cloud certification;
- Skilled with Firebase as a backend platform;
- Experience CI/CD, Docker, GitHub Actions, works according to Agile principles;
- Interested in implementing AI models in production solutions.
Main Skills
Kotlin 5 yr.
Java 5 yr.
Programming Languages
Android Libraries and Tools
Mobile Frameworks and Libraries
JavaScript Libraries and Tools
Java Frameworks
Data Analysis and Visualization Technologies
Databases & Management Systems / ORM
Cloud Platforms, Services & Computing
Amazon Web Services
Azure Cloud Services
Methodologies, Paradigms and Patterns
Platforms
SDK / API and Integrations
Third Party Tools / IDEs / SDK / Services
QA, Test Automation, Security
Collaboration, Task & Issue Tracking
Deployment, CI/CD & Administration
Virtualization, Containers and Orchestration
Version Control
Mail / Network Protocols / Data transfer
Message/Queue/Task Brokers
UI/UX/Wireframing
Other Technical Skills
Work Experience
Lead Engineer, Box12
Duration: May 2024 - Present
Summary: Leads the development of an ecosystem of fitness applications and services that enhance user experience and engagement in gym training. Responsible for full-cycle architecture design, development, and team leadership.
Responsibilities:
- Designed and implemented mobile app architectures using Jetpack Compose and MVI.
- Managed a cross-functional team of 5 (Android, Backend, QA, DevOps).
- Conducted mentoring sessions, introduced performance metrics and reward systems.
- Rebuilt the legacy codebase to improve scalability and user experience.
- Focused on user retention strategies through UX optimization.
Technologies: Kotlin, Android SDK, Firebase, Jetpack Compose, Jetpack Multiplatform Mobile, Retrofit, Koin, Room, Coroutines, Flow, GCP, Google Material Design, PostgreSQL, Firebase, Jira, GitHub, Confluence, Android Studio, GCP Console, Cloud AI.
Back-end Kotlin Engineer, Capgemini Engineering
Duration: Jun 2023 - Apr 2024
Summary: Developed backend solutions for AI-powered healthcare systems serving Indian clinics and hospitals. Focused on performance, distributed systems, and data optimization.
Responsibilities:
- Built API solutions using Kotlin, Spring Boot, and PostgreSQL.
- Integrated TimeScaleDB for 10x faster data processing and 3x space efficiency.
- Implemented Kafka-based asynchronous workflows and Keycloak authentication.
- Reduced DB load by 20% through caching decoupling and configuration service optimization.
- Maintained production monitoring and compatibility across distributed systems.
Technologies: Kotlin, Java 21, Spring Boot 3.2.2, Spring 6+, Keycloak, FHIR, Retrofit, Kafka, JUnit, Mockito, Jenkins, Oracle, PostgreSQL, TimeScaleDB, Jira, GitLab, Confluence, IntelliJ IDEA, Checkstyle, Figma, Excel, Swagger.
Back-end and Android Engineer, Globallogic
Duration: Jan 2022 - May 2023
Summary: Worked on Java/Kotlin desktop and Android applications for global telecom (Verizon) and healthcare (Samsung) clients, including AI and voice assistant integrations.
Responsibilities:
- Developed Kotlin Multiplatform Mobile (KMM) apps with Jetpack Compose and Firebase.
- Built full-stack features across web and desktop using JavaFX/TornadoFX.
- Integrated Amazon S3, AWS Lambda, and GCP ML services.
- Ensured product stability and rapid feature delivery through CI/CD pipelines.
Technologies: Kotlin, Java 17, Firebase, JavaFX, TornadoFX, KMM, Jetpack Compose, Ktor, Retrofit, Dagger, RxJava 2, Coroutines, Flow, AWS (S3, EC2, Lambda, ECS), PostgreSQL, Firebase, Jira, GitLab, Confluence, IntelliJ IDEA, Android Studio, Docker, AWS Console, Amazon S3.
Back-end Software Engineer, Business Information & CrowdFund Platforms
Duration: Apr 2021 - Dec 2021
Summary: Built scalable backend systems for business information management and a crowdsourcing platform. Contributed to BikeShare Ireland backend and enrichment systems.
Responsibilities:
- Developed RESTful APIs using Java and Spring Boot.
- Applied TDD and best practices for backend quality assurance.
- Supported existing platforms and built new features from scratch.
- Participated in low-level design discussions and architecture improvements.
Technologies: Java 11, Spring, Spring Boot, Maven, SQL, REST, Mockito, Tomcat, TypeScript, Angular CLI, PostgreSQL, MySQL, Jira, Bitbucket, Confluence, SonarQube, IntelliJ IDEA, Checkstyle, Docker.
Big Data Java Developer, BMW
Duration: Jul 2019 - Mar 2021
Summary: Worked on a large-scale big data solution for the BMW automotive sector, focusing on analytics, data processing, and system optimization.
Responsibilities:
- Built and optimized SQL-based analytical pipelines using Apache Spark.
- Developed scripts for data migration between Spark and Spring.
- Refactored legacy code, improving maintainability and reducing technical debt.
- Participated in developer training and feature enhancement initiatives.
Technologies: Java 8, Apache Spark, Tomcat 8.5, MySQL, Bitbucket, Jira (Scrum + Kanban).
Software Engineer, “Glory to the Nation Foundation”
Duration: Jan 2019 - Apr 2019
Summary: Developed a data-sharing system for public procurement transparency.
Responsibilities:
- Built C#-based desktop modules with MSSQL integration.
- Designed reporting and statistical visualization features.
Technologies: C#, MSSQL, WPF, WinForms, ASP.NET, Entity Framework, GitHub.
Software Engineer, Estella
Duration: Jul 2018 - Jan 2019
Summary: Developed software for managing furniture warehouse operations.
Responsibilities:
- Built both desktop and web versions of warehouse management tools.
- Integrated business logic and database layer for inventory operations.
Technologies: C#, MSSQL, WPF, WinForms, ASP.NET, Entity Framework, GitHub.
Work Sample
Vide - Event Interaction Platform (Commercial Project)
Client: Confidential
Platform: Android
Summary: Commercial Android application developed for a client. The product provides functionality for managing events, sessions, and targets within an interactive media environment.
Role: Engineer in the development team.
Technologies: Kotlin, Android SDK, Jetpack Compose, Firebase, GCP
Examples: https://drive.google.com/drive/folders/1I_Z622qV1BgGle68Db7qdgB098-14U8Y?usp=sharing
Education
- Master’s Degree in Software Engineering, Polytechnic National University (NULP) (Graduation Year: 2019)
- Bachelor’s Degree in Software Engineering, Polytechnic National University (NULP), Ukraine (Graduation Year: 2017)
Licenses & Certifications
- Google Cloud Professional Cloud Developer
- Coursera: Software Design and Architecture
- Bobocode: Kotlin Developer Path
- Mastermind: Android Architecture Advanced
Mentoring & Leadership
- Mentor at Bobocode Academy, guiding junior developers in Kotlin and backend development;
- Conducted internal tech sessions on Kotlin Multiplatform, Spring Boot, and Clean Architecture;
- Supervised a team of 5 developers and led system design reviews across multiple projects.