Adnan Kukuljac, Software Developer in Sarajevo, Federation of Bosnia and Herzegovina, Bosnia and Herzegovina
Adnan Kukuljac

Software Developer in Sarajevo, Federation of Bosnia and Herzegovina, Bosnia and Herzegovina

Member since December 19, 2014
Adnan is an experienced software engineer with a Bachelor’s and Master’s degree in Computer Science and about six years of professional experience including working on various solutions serving a couple of users to solutions serving millions of customers worldwide. Adnan's latest accomplishments include software performance improvements and decreasing client expenses by $15,000 per week as well as collaborating with more than 30 teams.
Adnan is now available for hire




Sarajevo, Federation of Bosnia and Herzegovina, Bosnia and Herzegovina



Preferred Environment

OS X, Git, InteliJ IDEA

The most amazing...

...thing I've coded is a Java software which helps Bioengineers in researching and processing DNA sequence.


  • Software Engineer

    2016 - 2019
    Zalando SE
    • Implemented a Cassandra token store which served as temporary solution to solve a Redis issue we had at that time.
    • Improved performance and design issues which led to 30% reduction in costs for servers.
    • Implemented tracking of business events which helped us to measure key metrics and improve stability.
    • Created newsletter hash login with AES algorithm.
    • Integrated with Fedex and Colissimo services (pickup, point, and return).
    Technologies: Java, Redis, Cassandra, DynamoDB, MySQL
  • Software Engineer

    2018 - 2018
    Acupic (via Toptal)
    • Fixed issues in existing web application and prepare it to go live.
    • Improved overall code quality by reducing duplicated files/code and introduced version control system which previous developers didn't use.
    • Implemented necessary changes which ensured that application is working smoothly in web-view (mobile application).
    Technologies: PHP, JavaScript
  • PHP developer

    2017 - 2017
    Scrappygram (via Toptal)
    • Implemented class that is responsible for uploading/downloading files to S3 (AWS).
    • Fixed the bug with using SendGrid SDK on Heroku (mbstring extension missing on Heroku).
    • Created guidelines and a development roadmap.
    • Fixed security issues on existing implementation.
    • Improved testing process for the API.
    Technologies: PHP, PostgreSQL, AWS
  • Software Engineer

    2015 - 2016
    Dilax Intelcom
    • Implemented algorithm to efficiently generate sensor data (Scala).
    • Contributed to development of back-end in Java (Spring) for Dilax's people counting software.
    • Participated in developing front-end in AngularJS for Dilax's people counting software.
    • Participated in knowledge transfer when Dilax Intelcom acquired “42Reports” company which allowed them a simpler process of acquiring the company.
    • Improved two internal software solutions which are written in Java (Spring).
    Technologies: Java, Scala, Angular, PostgreSQL
  • Software Engineer

    2014 - 2015
    • Developed a Hadoop MapReduce for Epinomics company which allowed them to efficiently store DNA sequence in Cassandra.
    • Built a Python pipeline on top of Luigi which allowed Epinomics team to analyze the data faster.
    • Automated the process of creating a cluster on AWS on top of StarCluster and starting various jobs which lowered costs and increased efficiency.
    • Developed the back-end for Epinomics web application which is used by Bioinformatics engineers to track analyses of DNA and helped them to analyze the data.
    Technologies: Java, Python, Cassandra, MySQL, Redis, StarCluster, AWS, Hadoop (MapReduce)
  • Software Engineer

    2013 - 2014
    Izum Web
    • Developed a module which interacted with 3rd party solution to provide nearest Danish post offices based on ZIP code.
    • Built a module which allows shop owners to easily manage ePay transactions.
    • Implemented a web service to synchronize stock between a physical store and online web shop.
    • Participated in developing various eCommerce websites.
    Technologies: PHP
  • Software Engineer

    2012 - 2013
    • Contributed to the development of an algorithm which was able to generate math tasks for kids based on their previous test results.
    • Participated in developing the back-end part of a web application which allows children to test their knowledge and, based on test results, provide exercises for improvement.
    Technologies: C#, ASP.NET, MySQL


  • Contributed to Monaliza Library (Development)

    Contributed to Monaliza library which is an image faker library used to test all sorts of applications where it comes to use of images.

  • (Development)

    Hobby project which I developed in order to allow faster and more interesting Q&A sessions after presentation.

  • Android MoneyFlow App (Development)

    Hobby project - MoneyFlow help you to track and manage your money. Each section is intuitively organized to give you the big picture of your finances. With this application, you can very fast and very easy to add and see your expenses

  • Fahrschein (Development)

    Contributed to Zalando open source project.

  • JS Logger (Development)

    Contributed to JS logger.

  • Zalando Lounge (Development)

    Implemented all catalog related and authentication related topics.

  • Microservice Communication: A Spring Integration Tutorial with Redis (Publication)
    Spring Integration enables lightweight messaging within Spring-based applications. In this article, Toptal Java Developer Adnan Kukuljac shows how Spring Integration with Redis makes it easy to build a microservice architecture.


  • Languages

    Java, PHP, JavaScript
  • Frameworks

    Play, Yii 1, Spring, CodeIgniter, Angular, Laravel
  • Libraries/APIs

    jQuery, Twitter API, Facebook API
  • Tools

  • Platforms

  • Storage

    Cassandra, PostgreSQL, MySQL, MongoDB, AWS DynamoDB
  • Paradigms

    Agile Software Development, Concurrent Programming, Kanban, E2E Testing


  • Master's degree in Computer Science
    2012 - 2014
    Faculty of Electrical Engineering, University of Sarajevo - Sarajevo
  • Bachelor's degree in Computer Science
    2008 - 2012
    Faculty of Electrical Engineering, University of Sarajevo - Sarajevo

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