Denis K.

Software Engineer | Backend | Fintech | Trading Systems | Crypto

United States

About

Passionate Software Engineer with 20 years’ experience in development of enterprise grade back-end and full-stack solutions for companies in the Finance industry. Critical thinker with strong analytical and problem-solving skills. Supportive team player with good interpersonal and communication skills, able to lead a team. Seasoned Developer with solid practical knowledge of design patterns and performance optimization techniques. Strong Claude skills.

Experience

  • Senior Software Engineer II at NinjaTrader
    Apr 2026 - Present · 3 mos

  • Senior Software Engineer at Gemini
    Apr 2022 - Feb 2026 · 3 yrs 11 mos

    Trading Core: Cryptocurrency Exchange core; Bitria: Trading system for institutional clients. * Delivered the Block Trading RFQ feature for the Trading system, which helped to increase revenue by 30%. * Designed and Implemented new Orders API for the exchange using more efficient DB tech to fit increasing load. * Designed and Implemented PnL persister service for the exchange. Set up the infrastructure for the PnL project. * Refactored and fixed numerous issues in Trading system engine bringing successful transactions rate to 99.9+%. * Developed the Closed Orders processing services for the Exchange core. * Created technical specifications. Performed design reviews. Mentored junior developers.

  • AVP (Software Engineering) at Barclays Corporate & Investment Bank
    Sep 2020 - Apr 2022 · 1 yr 8 mos

    Design and development of Equity Derivatives trading system. • Developed new features leveraging a wide technology stack, including Java, C#, TypeScript and Oracle DB. • Efficiently communicating with downstream teams when working on inter-system integration services to deliver business-critical functionality for regulatory compliance. • Finding flows in the system's platform design and proposing solutions to fix. Technologies: Java, Spring, C#, WCF, TypeScript, JavaScript, HTML5, Angular, Oracle DB, SQL, git, Python, Perl, Autosys

  • Senior Software Engineer at Refinitiv
    Oct 2018 - Dec 2019 · 1 yr 3 mos

    Analytics Data Cloud: Global financial market data distribution system – API, DBs and ETL solution. • Improved response time and optimized resource usage by adding cache, tuning queries and algorithms • Uncovered numerous performance flows in the API by creating a Performance Statistics Analyzer tool • Acted as a Scrum master and led a team of 5 remote consultants in a system performance improvement stream • Reduced number of bugs in my team by 50% by enforcing GitFlow with code review and writing acceptance tests • Implemented ETL workflows (XML and JSON => HBase and SQL DB) and API handlers for them Technologies: Python, Django, C#, Multithreading, WCF, MySQL, HBase, Spark, Kafka, Linux, Docker, Actian Vector, AWS, Amazon Aurora, Redshift, NUnit, git, JMeter

  • Senior Software Engineer at Thomson Reuters
    Mar 2017 - Oct 2018 · 1 yr 8 mos