@ykrupin

Hi there, I'm Yevhen 👋🏻

Author of code that fuels the very heart of Amazon's infrastructure . Experienced software engineer focused on delivering reliable, tested, high-performance solutions. Equally effective as a collaborative team player and as an individual contributor.

With over a decade of experience, I have developed deep expertise in:
Java 8-21 (JDK, JVM internals, Spring Boot, Async Profiler), .NET (C#, WPF, ASP.NET, Xamarin), C++, TypeScript, React, AWS, Google Cloud, relational and NoSql databases.

I speak three languages:
Ukrainian, English and French.

Let's Connect

Please, feel free to reach out to me, I am always available for interesting projects and consulting.

Work Experience
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  • Jan2023 - current
    Amazon / AWS, Language & Library Foundations, Dublin, Ireland
    Software Development Engineer

    Technologies: Java 8-21, C++, AWS services, Async Profiler, Amazon Profiler, JMH, JMX, JFR, JUnit, Gradle, Maven, internal Amazon tools.

    • Led early-access customer engagement across 10 services, driving the product’s global availability at Amazon.
    • Delivered core features of the Java runtime, enabling the upgrade of 4.5K services across more than 2.6MM hosts to run on the latest LTS JVM without code change.
    • Unlocked the upgrade of core Amazon retail service handling 350MM+ requests per day, increasing TPS by 13-20%, decreasing CPU utilization by 10-30%, and latency by 15-25%, while reducing host count by up to 50%.
    • Coached 2 junior engineers through pair programming and code review; created technical documentation improving onboarding for new members.
    • Enhanced automated testing harness to enable running tests across 4 JDK versions.
  • Mar2020 - Dec2022
    CERN, Switzerland
    Senior Fellow/Software Engineer

    Technologies: Java 11, Spring Boot, TypeScript, React, Oracle SQL, JDBC, JPA, Liquibase, Keycloak, Junit, Mockito, Docker.

    • Delivered and maintained document handling service (processing 500K documents/year), recruitment systems, CERN phone book (1500+ unique daily visits);
    • Automated HR and recruitment processes, handling 3,000+ registrations per year;
    • Enhanced software quality and processes through agile practices, pair programming, refactoring etc;
    • Mentored junior engineers and colleagues;
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