Looking for a job

Дмитрий Грищенко

@0008512

Software Architect and Java Tech Lead at Kyivstar, building OMNI, an active-active event-driven platform, and Gadfly, a voice tutor for tech interviews.

United Kingdom

Message

What I'm looking for

I’m open to architecture and engineering leadership roles, and I’m also interested in conversations about interview preparation or Gadfly.

At Kyivstar, I’m the Software Architect and Tech Lead for OMNI, an event-driven platform that decides in real time what subscribers see in USSD and the My Kyivstar app. I shape its Kafka-based architecture and active-active on-premises design, with Java 21 and Spring Boot services.

Since July 2026, I’ve also built Gadfly from an empty repository into a live voice tutor for technical interviews. I built its backend with Python and FastAPI, its web app with Next.js and React, and its in-browser voice pipeline so raw audio stays on the user’s machine.

Before Kyivstar, I worked at JPMorgan Chase, Ciklum, Playtech and Thomas Cook in software engineering and architecture roles. I started in Java development after working in network and systems engineering, and I’m happy to talk about architecture and engineering leadership roles, interview preparation, or Gadfly.

Experience

Work history, roles, and key accomplishments

Current

Founder, Owner & CTO

Current

Gadfly

Jul 2026 - Present (4 months)

Gadfly (usegadfly.com) is a voice tutor for technical interview practice. Engineers work through algorithms, system design and behavioral rounds out loud. Gadfly asks the next question instead of handing over the answer, names the weakness behind what broke, and brings it back on a schedule until it clears.

As founder and CTO I own the product end to end: idea, architecture, code, infrastructure

Current

Software Architect / Java Tech Lead

Current

Київстар

Mar 2025 - Present (1 year 8 months)

Software Architect and Tech Lead for OMNI at Kyivstar, Ukraine's largest mobile operator: an event-driven channel-orchestration platform that decides in real time what a subscriber sees in USSD and the My Kyivstar app, built to run active-active on-premises.

Scope and results
• Own the architecture: domain-driven design, bounded contexts, Apache Kafka as the backbone, Kafka Streams for stream pro

VP Lead Software Engineer

JPMorgan Chase & Co.

May 2023 - Dec 2024 (1 year 7 months)

Worked as VP Lead Software Engineer at JPMorgan Chase & Co..

Co-founder/CTO

Winqod

Jan 2020 - Sep 2024 (4 years 8 months)

Worked as Co-founder/CTO at Winqod.

Java Technical Lead

Ciklum

Dec 2021 - Oct 2023 (1 year 10 months)

Worked as Java Technical Lead at Ciklum.

Software System Architect

Playtech

Oct 2019 - Oct 2021 (2 years)

Worked as Software System Architect at Playtech.

Solutions Architect

Thomas Cook

Mar 2017 - Sep 2019 (2 years 6 months)

Worked as Solutions Architect at Thomas Cook.

Senior Software Engineer

EPAM Systems

Jul 2015 - Apr 2017 (1 year 9 months)

Worked as Senior Software Engineer at EPAM Systems.

Java Developer

EngagePoint, Inc.

Aug 2013 - Jun 2015 (1 year 10 months)

Java developer on products and Jira plug-ins for a US software vendor: Java, JAX-RS, Atlassian SDK, Maven, Jenkins. Projects: EngagePoint Transparency (a public transparency portal) and Questionnaire Wizard. First commercial development role after four years in network and systems engineering.

Wireless Engineer

DICS

Mar 2011 - Aug 2013 (2 years 5 months)

Designed, deployed and supported the wireless infrastructure of the NSC Olympiyskiy stadium in Kyiv: access points, wireless controllers, the wireless network management and monitoring systems, security configuration and analysis of the wireless network.

System Administrator

“BSM” (Business solution for management)

Feb 2010 - Mar 2011 (1 year 1 month)

Support for Park 200 pcs. Customer Support. Server Configuration (Hardware + Software) Windows 2003 to Windows 2008, FreeBSD. Setting the switches, routers. Planning and implementation of the transition from Windows 2003 to Windows 2008 + licensing. Support for anti-virus policies. Supports archiving policy.

Senior System Administrator

Polyana Ukrainian Group

Jun 2009 - Feb 2010 (8 months)

Creation of IT infrastructure for a distributed network of retailers. Develop a strategy of IT infrastructure. Search for contractors to perform work on the installation of SCS, surveillance video, music. The signing of contracts with suppliers of telecommunications services. Purchase of the necessary IT equipment for the operation of stores and offices. Server Configuration (Hardware + Software),

System Administrator

VD ONE Company

Aug 2007 - Jun 2009 (1 year 10 months)

Support and development of the IT infrastructure of retail stores, server support SUSE Linux Enterprise, FreeBSD, Windows 2003. Support mails, terminal server, file storage, server 1C. 1C accounting analyst. Customer Support. Work with suppliers tel. services. Support for anti-virus policies. Finished 6 stores, head office and warehouse 2.