Cosmin Mavrichi
Verified Expert in Engineering
Software Developer
Bucharest, Romania
Toptal member since December 24, 2024
Cosmin is a skilled Kotlin/Java developer with over five years of experience building and optimizing microservices. He has worked with technologies like Kotlin, Java, Spring Boot, PostgreSQL, AWS, Apache Kafka, and Elasticsearch, continually focusing on improving system performance, ensuring reliability, and automating infrastructure. Cosmin has a strong track record in troubleshooting, optimizing code, and delivering efficient back-end and full-stack development solutions.
Portfolio
Experience
- Spring Boot - 6 years
- Java - 6 years
- Hibernate - 6 years
- REST APIs - 6 years
- Elastic - 4 years
- Kotlin - 3 years
- Azure - 3 years
- Amazon Web Services (AWS) - 2 years
Availability
Preferred Environment
Java, Kotlin, Azure, Spring 6, Spring Boot
The most amazing...
...solution I've developed is an AI-powered assistant that streamlines content discovery, improving search efficiency for advertising scenes.
Work Experience
Senior Software Engineer
MIRRIAD
- Optimized file copy performance within Azure Blob Storage, reducing the time to transfer a 500 GB file from 50 minutes to one minute by implementing parallel transfer techniques and efficient storage management.
- Decreased Elasticsearch re-indexing time from 5 to 1.5 hours by optimizing workflows, improving data availability, and enhancing developer efficiency.
- Developed a Kotlin-based AI-powered assistant, enabling users to search a vast content library and locate advertising scenes efficiently, streamlining the content discovery process.
- Improved SQL performance for MySQL and Azure SQL, achieving significant query execution efficiency and reducing database load.
- Managed infrastructure consistency with Terraform, creating infrastructure-as-code pipelines that simplified microservices deployment and scaling.
- Increased microservices test coverage to 80%, reducing bugs and improving release stability by applying rigorous unit and integration testing practices.
Java Software Engineer
NatWest Group
- Built flexible mortgage application microservices in Java, contributing to a high-performing platform for Natwest Bank's clients.
- Mentored and onboarded new team members, facilitating their integration into the codebase and accelerating their productivity.
- Identified and resolved critical bugs in mortgage workflows, minimizing system disruptions and improving reliability.
- Collaborated with cross-functional teams, ensuring timely delivery of key features aligned with client requirements.
Full-stack Developer
TripAdvisor
- Implemented a drag-and-drop photo gallery in React, streamlining user workflows for managing image order and enhancing UX.
- Refactored monolithic architecture into microservices, leveraging Java 11, Jersey, and Swagger to improve scalability and modularity.
- Optimized PostgreSQL ETLs, reducing execution time by 50%, significantly improving data pipeline efficiency.
- Enhanced system observability by integrating Prometheus metrics and alerting, improving issue detection and resolution times.
- Designed and added new Apache Avro schemas to track and aggregate data on ad impacts across the platform, enabling precise insights into their effectiveness.
- Leveraged Presto to query and analyze ad click data, providing timely insights that informed platform optimization strategies.
- Created Snowflake dashboards to visualize aggregated data, enabling business teams to monitor key metrics and drive data-driven decisions.
Java Developer
UniCredit
- Developed a barcode parsing microservice, processing around 3,000 daily requests and replacing legacy systems for improved efficiency.
- Migrated the exchange rate application from Java 7 to Java 8, introducing new features like a "Happy Hour" exchange rate to attract customers.
- Automated card team reports, reducing manual effort and improving productivity.
- Refactored legacy libraries to comply with Java 8 standards, improving code readability and maintainability.
Java Developer
Pentalog
- Developed a Spring Boot back-end application to manage the internal contractors, adhering to best practices like N-tier architecture and using data transfer objects (DTO) to improve maintainability.
- Implemented unit testing with JUnit 5 and Mockito, increasing code quality and reliability.
- Collaborated within Agile sprint cycles, delivering features iteratively and maintaining clear communication with stakeholders.
Experience
Document Management System
Education
Bachelor's Degree in Computer Science
Vasile Alecsandri University of Bacău - Bacău, Romania
Skills
Libraries/APIs
REST APIs, Reactor, React, OpenAPI
Tools
Apache Maven, Elastic, TeamCity, Gradle, Terraform, Apache Avro, Amazon Simple Queue Service (SQS)
Languages
Java, Kotlin, SQL, JavaScript, Snowflake
Frameworks
Spring 6, Spring Boot, Hibernate, JPA, JUnit 5, Mockito, Swagger, Jersey, Presto, Hadoop, Spring 3, Spring 4, Spring Batch
Paradigms
REST, Microservices, ETL, Agile
Storage
Databases, PostgreSQL, Amazon S3 (AWS S3), MySQL, Azure SQL
Platforms
Azure, Docker, Oracle Database, Apache Kafka, Jakarta EE, Amazon Web Services (AWS)
Other
Algorithms, Data Structures, SOAP, Computer Science, Prometheus, Data Transfer Objects (DTO), Amazon RDS
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