Alexey Saenko, Software Developer in Berlin, Germany
Alexey Saenko

Software Developer in Berlin, Germany

Member since January 24, 2016
Alexey has more than 13 years of experience in research and development of a wide range of software from small and short-term projects to huge and complicated enterprise systems mostly specializing in server-side development. He really enjoys creating high-quality software, writing clean and clear code, and solving intellectual challenges.
Alexey is now available for hire




Berlin, Germany



Preferred Environment

Ubuntu, IntelliJ IDEA, Git

The most amazing...

...tool I've designed and implemented detects bacteria in foods with more than 90% efficiency using mathematical image processing and fuzzy logic.


  • Software Architect

    2016 - PRESENT
    Market Logic
    • Designed and implemented a large-scale distributed information retrieval system with scalable data mining and retrieval.
    • Developed a scalable newsletter service.
    • Designed and implemented a Spring Batch based application for scheduled execution of a big set of jobs.
    Technologies: Java SE 8, Spring Boot, Spring Batch, Spring MVC REST, Elasticsearch
  • Senior Java Developer

    2017 - 2017
    William & Rahman, Ltd. (via Toptal)
    • Created a prototype of an automated trading system.
    • Introduced CI based on GitLab CI and Maven.
    Technologies: Java SE 8, Interactive Brokers API
  • Senior Java Developer

    2016 - 2017
    Outcome Engenuity, LLC (via Toptal)
    • Created a reusable diagram building tool.
    • Implemented responsive UI with JavaFX.
    • Introduced Maven build manager.
    • Supported REST service calls on the client side.
    Technologies: Java SE 8, JavaFX, JAX-RS, Maven
  • Senior Java Developer

    2013 - 2016
    • Created an application from scratch that brings together all public transportation companies of Switzerland into a single software platform for ticketing and customer service.
    • Developed and supported an online contract management system for Deutsche Telekom.
    • Migrated a few projects from EJB to Spring.
    • Migrated plenty of services from RMI to SOAP (Spring WS and Apache CXF implementations).
    • Created a universal object conversion framework.
    Technologies: Java SE 7, Gradle/Maven, WebSphere/Weblogic, Hibernate, Spring, Apache CXF, JUnit, EasyMock
  • Senior Java Developer

    2014 - 2015
    • Developed an application that charted and interacted with a general-purpose external USB data logger.
    • Developed an AWS gateway for storing and sharing files.
    • Reported and fixed a lot of bugs within open source software products for the company.
    Technologies: Java SE 8, JavaFX, Swing, JFreeChart
  • Visiting Researcher

    2012 - 2013
    Ilmenau University of Technology
    • Designed and implemented a digital image segmentation algorithm.
    • Developed a fuzzy classifier for immunological detection of bacteria in foodstuff.
    • Implemented a desktop application to prepare test data to train the classifier.
    Technologies: Java SE 7, Maven, Tomcat, Spring, JUnit
  • Senior Java Developer

    2010 - 2012
    • Developed an internal tool for skill and human resource management.
    • Created a billing system for ships going through rivers and harbors of Germany.
    • Created a Java language course for the students.
    Technologies: Java SE 6, Maven, Tomcat, Hibernate, Spring, Apache CXF, JUnit, EasyMock
  • Java Developer

    2007 - 2010
    Exigen Services
    • Developed and supported a J2EE module for processing and validating XML-formed orders.
    • Created a tool for parsing a set of error messages with Apache POI from the Excel file.
    • Improved the conversion between XML data structures with XSLT.
    Technologies: Java SE 5, Ant, JBoss 4.2.1, JMS, JMX, XML/XSD/XSLT, JAXB/XMLBeans, JUnit, EasyMock


  • (Development)

    Simple AWS gateway for storing and sharing files

  • Spring Batch Tutorial: Batch Processing Made Easy with Spring (Publication)
    Spring Batch is a lightweight, comprehensive framework designed to facilitate the development of robust batch applications. It’s easy to set up, and even easier to use. In this article, Toptal Freelance Software Engineer Alexey Saenko explains the programming model and the domain language of batch applications, using detailed code examples that should help any developer looking to get a head start in Spring Batch.
  • Toptal Mentor
    Alexey is a mentor in the Toptal Global Mentor’s Program. This program is a partnership between Toptal and General Assembly to provide high quality mentorship for students from minority and low income backgrounds who are looking to begin their careers as professional software engineers. Alexey shows commitment to diversity in tech by mentoring a General Assembly student every week for a year, covering everything from coding tips and tricks to advice on making it in the industry.


  • Languages

    Core Java (J2EE), XML/XSLT, SQL, Hibernate Query Language (HQL), XSD, Java, CSS, JavaScript, HTML, Python, C++
  • Frameworks

    Spring, Spring Batch, Swing, Spring MVC, Apache CXF, Spring Boot, Selenium, Hibernate, JPA, OAuth 2, XMLBeans, GRPC, Swagger
  • Libraries/APIs

    JAX-WS, JAX-RS, JAXB, Spring REST, JMS, Java Servlets, Apache Lucene, Interactive Brokers' API
  • Tools

    GitHub, Maven, Git, Subversion (SVN), AWS Step Functions, Java Concurrency, SoapUI, Apache Tomcat, LaTeX, Jenkins, GitLab CI/CD, Apache Solr, MATLAB, Gradle, Apache Ant, GitLab
  • Paradigms

    Continuous Integration (CI), REST, Object-oriented Programming (OOP), Object-oriented Design (OOD)
  • Platforms

    Java EE, JSE, AWS Lambda, Apache Kafka, Docker, JavaFX, Oracle, Linux, JBoss, Kubernetes
  • Storage

    JSON, Elasticsearch, MySQL, PostgreSQL, H2, AWS DynamoDB, MongoDB, NoSQL, AWS S3, Cassandra
  • Other

    SOAP, EJB, Network Protocols, SSL, NIO, Sparx Enterprise Architecture, OAuth, Fuzzy Logic, Mathematics, Serverless, AWS


  • Master of Science degree in Mechatronics
    2008 - 2010
    University of Information Technologies, Mechanics, and Optics - St. Petersburg, Russia
  • Bachelor of Science degree in Mechatronics
    2004 - 2008
    University of Information Technologies, Mechanics, and Optics - St. Petersburg, Russia


  • Oracle Certified Expert, Java EE 6 Web Services Developer
    JUNE 2012 - PRESENT
    Oracle (ID SR5369041)
  • Sun Certified Business Component Developer for the Java Platform, EE 5
    Sun Microsystems (ID SR5369041)
  • Sun Certified Programmer for the Java Platform, Standard Edition 6
    Sun Microsystems (ID SR5369041)

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