carlos calero albelo
IT PROFESSIONAL ENGINEER
ANDROID DEVELOPER | BACKEND | QA EXPERTISE
CONTACT
--https://calerohq.dev
Wrocław, Poland
PROFILE
Backend and Android Developer with 8+ years of experience
building and optimizing native applications and cloud-based
services. Led QA teams and contributed to high-demand
projects in healthcare, sports entertainment, and social
media.
Passionate
about
clean
architecture,
performance, and continuous value delivery.
LANGUAGES
WORK EXPERIENCE
English (Advanced)
Dspot Sp. z o. o. (2016 – 2023, 2024 – 2025)
Spanish (Native)
TECHNOLOGIES
BACKEND
Java
Spring Boot
Hibernate
MySQL
MongoDB
Redis
Docker
Maven
Gradle
RESTful APIs
Service-oriented
architecture
ANDROID
Kotlin
Java
Android SDK
Jetpack Compose
Android Architecture
Components
high
Backend and Android Developer
Developed and maintained 10+ native Android applications
using Java and Kotlin, ensuring top-tier performance and
reliability.
Led in-depth code reviews to uphold coding standards and best
practices.
Implemented unit tests and resolved critical issues—such as
crashes, memory leaks, and concurrency problems—using
Mockito, JUnit, Espresso, and Cucumber.
Integrated Android applications with various web services and
third-party libraries (Firebase, Retrofit, Facebook SDK, Picasso,
Glide, Papertrail, MixPanel) to enhance functionality and user
engagement.
Analyzed design specifications and engineering documentation,
providing actionable feedback to optimize performance and
usability.
Adopted
Agile
methodologies
(Scrum)
to
improve
team
collaboration and streamline sprint planning.
Created advanced features leveraging Bluetooth Low Energy
(BLE) technology to support innovative product functionality.
I agree to the processing of personal data provided in this document for realising the recruitment process pursuant to the Personal Data Protection Act of 10 May 2018 (Journal of Laws 2018,
item 1000) and in agreement with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of
personal data and on the free movement of such data, and repealing Directive 95/46/EC (General Data Protection Regulation).
MVVM/MVI (Clean
architecture patterns)
Retrofit, Firebase
Bluetooth Low Energy
(BLE)
Local Storage: SQLite,
Realm, SharedPreferences
OpsTalent Sp. z o. o. (2023 – 2024)
Backend Developer
Spearheaded the design and implementation of RESTful APIs
using Java Spring Boot, ensuring scalable and maintainable
systems.
Optimized database queries and integrated Redis caching,
boosting overall application performance.
QA
JUnit, Mockito
UI & Automated Testing
with Espresso, Selenium,
Cucumber
Test Strategy & Coverage:
Test case design and
execution, CI/CD pipeline
integration, coverage
reports
EDUCATION
Informatics Sciences
Engineer - University of
Informatics Sciences, La
Habana, Cuba,
2009 - 2014
Developed
and
supervised
a
microservices
architecture,
improving reliability and deployment efficiency.
Led the migration of legacy databases to MongoDB and MySQL,
enhancing data storage capabilities and scalability.
Established comprehensive testing strategies using JUnit and
Mockito, achieving high code coverage and reliable software
releases.
Championed best practices in test organization, reducing
technical debt and streamlining team workflows.
Integrated
CI/CD
pipelines
with
Jenkins,
automating
deployments and minimizing manual interventions.
Partnered with front-end teams for seamless API integration,
elevating the overall user experience.
Implemented secure authentication and authorization with
Spring Security, safeguarding user data.
ISTQB Certified Tester,
Foundation Level - ISQI,
La Habana, Cuba,
2016
Mentored junior developers, fostering a culture of continuous
improvement and high-quality code delivery.
CALISOFT, National Software Quality Center (2014 – 2016)
Kotlin for Java
Developers - Jetbrains
& Coursera, Wrocław,
Poland,
2023
www.coursera.org/verify/9WG7
KHP98457
Leading Test Engineer
Led a functional testing team responsible for designing and
executing automated and manual test cases across 20+
applications.
Developed comprehensive test plans and strategies, significantly
improving product reliability and quality assurance processes.
I agree to the processing of personal data provided in this document for realising the recruitment process pursuant to the Personal Data Protection Act of 10 May 2018 (Journal of Laws 2018,
item 1000) and in agreement with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of
personal data and on the free movement of such data, and repealing Directive 95/46/EC (General Data Protection Regulation).
SKILLS
PROJECTS
Excellent problem-solving
with keen attention to detail,
ensuring high-quality
outcomes.
Collaborative team player
who enjoys mentoring others
and building supportive work
environments.
Solid understanding of core
development principles,
resulting in reliable and userfriendly solutions.
Strong communicator, both
verbally and in writing, able to
explain ideas clearly and
effectively.
Quick to adapt to new tools
and processes, always open
to learning and growth.
Proven leadership, managing
and guiding teams toward
shared goals.
Effective time management
and organization, balancing
multiple tasks under tight
deadlines.
Analytical thinker, using data
and insights to make
informed decisions and
improve results.
Ostia Solutions: N-CAPIE (Backend)
HOBBIES
Sports
Cooking and Experimenting
with new recipes
Built a standards-based, No-Code SaaS solution to streamline
the design and deployment of enterprise-level API ecosystems.
Developed secure user authentication and authorization
protocols, enhancing application security.
Implemented a scalable microservices architecture, reducing
maintenance complexity and improving system performance.
Lanetalk (Android App)
Incorporated Papertrail, MixPanel, and Retrofit for comprehensive
real-time data tracking and analytics.
Enabled automated progress tracking and updates from any
location, keeping users consistently informed.
Implemented HTTP, REST, JSON, and XML integrations for reliable
data exchange.
Built user-centric Android UI components to enhance overall
engagement and ease of use.
EtectRx (Android App)
Integrated Papertrail and Retrofit to enhance logging, monitoring,
and data retrieval processes.
Automated device pairing and synchronization via Bluetooth Low
Energy (BLE), improving connectivity and user experience.
Utilized HTTP, REST, JSON, and XML for seamless web service
integration.
Crafted intuitive Android UI components to deliver a polished,
user-friendly interface.
Enksia (Android App)
Leveraged Firebase for real-time data synchronization, enabling
secure parental control features.
Engineered custom Android UI components designed for optimal
user engagement and usability.
Tutiz (Android App)
Integrated multiple payment and communication platforms
(PayPal, Stripe, Facebook, Intercom, Firebase), broadening user
options.
Developed a dynamic reservation system for class scheduling
based on subject availability, pricing, and teacher time slots.
Created personalized user profiles leveraging device features
and geolocation data.
Streamlined teacher searches with both simple and advanced
filtering, boosting user satisfaction and search efficiency.
I agree to the processing of personal data provided in this document for realising the recruitment process pursuant to the Personal Data Protection Act of 10 May 2018 (Journal of Laws 2018,
item 1000) and in agreement with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016 on the protection of natural persons with regard to the processing of
personal data and on the free movement of such data, and repealing Directive 95/46/EC (General Data Protection Regulation).
