Sam Kruglov, Software Developer in Miami, FL, United States
Sam Kruglov

Software Developer in Miami, FL, United States

Member since January 6, 2021
Sam is a senior Java back-end engineer with experience building synchronous, reactive, and event-driven distributed systems. He has achieved a 50% performance increase for web response times by redesigning the code. Sam has mentored junior developers, spoken at the DevClub conference, and created fast, flawless products through outstanding optimization. As a clean code evangelist, he enjoys taking ownership of every project and delivers maintainable and well-tested solutions that last.
Sam is now available for hire




Miami, FL, United States



Preferred Environment

Amazon Web Services (AWS), Kotlin, Java, Git, Spring, AWS

The most amazing...

...result I've achieved involved turning around the company architecture by advocating Event Sourcing and CQRS for a reactive microservices experience.


  • Software Engineer

    2021 - PRESENT
    • Collaborated on an ETL python project (Meltano) to download Facebook ads data.
    • Cooperated a little on the iOS app. Learned mobile fundamentals.
    • Implemented a C# cross-platform mobile app to measure the hearing aid’s wearing time and pass it to the main app with basic UI.
    Technologies: Java, Python, ETL
  • Software Engineer

    2020 - 2021
    • Researched how the bank could implement a new search project via Elasticsearch with all size estimations.
    • Integrated OpenAPI (Springdoc, Swagger, and OpenAPI Generator).
    • Implemented distributed cache (Hazelcast), migrated from Ehcache.
    Technologies: Spring, Java
  • Software Engineer

    2018 - 2020
    • Gave a talk on Event Sourcing & CQRS with Axon Framework internally and at a local conference. While attending the AxonIQ conference, arranged a meeting with our CTO and their founder which resulted in the company migrating to these patterns.
    • Achieved a 50% performance increase for average web response time by redesigning and reimplementing a big portion of the code.
    • Assisted to onboard and mentor a new junior Java developer.
    • Presented on API development which changed the company standard from REST to GraphQL.
    • Owned the microservice from writing code and deploying to production.
    Technologies: Spring, Java
  • Software Engineer

    2017 - 2018
    ORION Innovation
    • Learned Java stack from scratch while working long hours.
    • Took the initiative and wrote 100 pages of missing documentation for an old project.
    • Implemented and maintained the main microservice of 20,000 lines of code and its database schema.
    • Implemented a complex data collection service with dynamic custom XML configuration.
    Technologies: Spring, Java


  • Basic Users and Roles API

    A Java and Spring-based API for managing users and roles. The data is stored in a relational database in which schema is versioned. It's accessed via an ORM framework with a cache layer. The HTTP API is validated by JSR 380 and secured with JWT. OpenAPI is used for API documentation, client SDK generation (which is used for integration tests), and exposing Swagger UI.


  • Languages

    GraphQL, SQL, Kotlin, Python, Java, Bash, HTML, CSS, JavaScript, Groovy
  • Frameworks

    Spring, Spring Boot, JPA, Spring MVC, Hibernate, Axon Framework, Spring Security, Swagger, JSON Web Tokens (JWT), JUnit, Mockito
  • Libraries/APIs

    OpenAPI, REST APIs, AssertJ
  • Tools

    IntelliJ IDEA, Git, Flyway, Maven, Jenkins, Slack
  • Paradigms

    REST, Agile, Scrum, Testing, Event Sourcing, CQRS, Test-driven Development (TDD), Reactive Programming, ETL
  • Other

    Software Engineering, GitFlow, AWS, Reactive Streams, Validation, Hibernate Validators
  • Platforms

    Docker, Amazon Web Services (AWS), Unix, Linux
  • Storage

    Hazelcast, Spring Data JPA, Cache
  • Industry Expertise



  • Bachelor's Degree in Computer Science
    2013 - 2018
    Nizhny Novgorod State Technical University n.a. R.E. Alekseev - Nizhny Novgorod, Russia

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