Summary
I am a PhD-educated software architect with a proven record of solving complex technical challenges in large-scale, mission-critical environments. Drawing on my research background, I approach each problem systematically, balancing technical constraints and business priorities to deliver robust, high-performance solutions under tight deadlines.
I have some experience in several programming languages (Java, Kotlin, Go, Node.js) and databases (Oracle, MongoDB), as well as distributed systems, blockchain technologies, and modern cloud infrastructure. I have worked in several industries: Finance, Healthcare and Communications.
I excel at optimizing performance, enhancing security, scaling systems, and collaborating across teams worldwide to align technical and business goals. Alongside architecture and coding, I handle project management, guide teams, and negotiate solutions with stakeholders at every level.
As a hobby, I maintain a YouTube channel focused on distributed systems, where I share my knowledge. This unique mix of deep technical skill, research-driven thinking, and communication ability equips me to drive meaningful results in demanding engineering contexts.
Links & Contacts
The easiest way to contact me is to write me on linkedin
I speak English, Portuguese and Russian
Work
Senior Software Architect @ JettyCloud
Dec-2021 ⟶ Today • 4 years ( Promoted from Software Architect in Apr 2024)
JettyCloud is the technical center for RingCentral, a leader in UCaaS solutions. I’m part of a team of architects guiding a large-scale messaging platform—from its monolithic origins to a microservices-based architecture with over 50 interdependent services and a total engineering team of several dozens of people. My work spans both strategy and execution, ensuring we balance technical vision, business requirements, and operational realities.
Key Contributions:
• Authentication & Security: Defined the security roadmap and decomposed authentication into a dedicated service, enhancing both scalability and reliability.
• Scalability & Performance: Optimized data models, client-server protocols, and underlying infrastructure to support enterprise-scale usage and demanding edge cases.
• Service Mesh Integration: Designed and implemented the migration to an Istio-based service mesh, improving service-to-service communication and resilience.
• Feature Design & Delivery: Researched, designed, and introduced critical features (e.g., threading), and managed projects from conception through deployment.
• Cross-Functional Collaboration: Worked closely with frontend/backend engineers, product managers, and directors, aligning technical capabilities with business goals.
• Project Management: Led project execution, running regular syncs, creating actionable plans, and tracking progress to ensure timely, high-quality outcomes.
Blockchain & SSI Architect @ Luxoft
Oct-2020 ⟶ Dec-2021 • 1 y 3 m
Building on my blockchain experience, I took on a role balancing architecture and hands-on development to create a large-scale Self-Sovereign Identity (SSI) solution for healthcare, designed for hundreds of thousands of users. Working in coordination with a chief architect, I handled R&D efforts, architectural design, and active coding.
I led the research, design, and development of a Kotlin Multiplatform mobile library implementing the DIDComm protocol for Android and iOS, guiding other developers in this effort. Beyond mobile, I managed the migration of Corda-based systems to Kubernetes and maintained close collaboration with .NET developers and an Indian team responsible for Azure serverless components. I also served as a technical mentor, ensuring that all solution elements integrated seamlessly.
Key Contributions:
• Architected SSI solutions for a large healthcare ecosystem
• Researched DIDComm and led the creation of a Kotlin Multiplatform mobile library (github)
• Split time between architectural design, R&D, and coding responsibilities
• Migrated Corda-based components to Kubernetes
• Coordinated with globally distributed teams (including .NET and Azure) to align and streamline the solution
Blockchain Developer @ Luxoft
Jan-2019 ⟶ Oct-2020 • 1 y 10 m
Worked on R&D and production-level blockchain solutions involving self-sovereign identity, primarily using private distributed ledger technologies such as R3 Corda and Hyperledger Fabric. Developed proofs-of-concept for several clients and supported a production system for a U.S. healthcare startup. Leveraged containerization and cloud platforms, and made open-source contributions (fabric-utils, fabric-skeleton) to improve tooling.
Key Contributions:
• Designed and implemented CorDapps in Kotlin on the Corda platform and developed Go-based smart contracts for Hyperledger Fabric
• Built and integrated Java services supporting the blockchain ecosystem, handling messaging, data processing, and security
• Delivered successful POCs for multiple customers, tailoring solutions to meet specific business and compliance needs
• Maintained a production-grade, Kubernetes-based blockchain solution, ensuring performance, scalability, and reliability
• Deployed and managed solutions on Microsoft Azure for seamless integration and operations
Java Developer @ Luxoft
Nov-2016 ⟶ Jan-2019 • 2 y 3 m
Developed a real-time banking subsystem for the same large European investment bank, this time focusing on a separate set of Java-based services with strict performance and reliability requirements. The platform consisted of a dozen asynchronous services that routed and processed messages via JMS, integrated with multiple third-party systems, and required careful attention to concurrency and database transaction performance. Working closely with teams in Russia, India, the UK, and the US, I contributed to code design, performance tuning, and troubleshooting complex locking issues on Oracle databases. After achieving the project’s goals, we successfully transitioned its ongoing support and maintenance to the team in India.
Key Points:
• Designed and implemented Java services using Spring, Spring Integration, and JMS within a distributed, asynchronous architecture
• Focused on performance tuning, resolving concurrency issues, and optimizing database transactions on Oracle
• Collaborated with international teams and stakeholders, ensuring smooth communication and timely deliveries
• Completed project objectives and transferred final responsibilities to the India-based team
Perl/PLSQL/VB Developer @ Luxoft
Sep-2015 ⟶ Nov-2016 • 1 y 3 m
Led the migration of a large-scale PL/SQL application from an outdated booking and recording system to a newer platform. With strict deadlines and a “spaghetti” codebase, I took on ownership of the code analysis, development, and delivery phases. Using my deep domain knowledge from previous support roles, I reworked integrations, refined business logic, and drove the project forward—while coordinating with various teams to manage dependencies and ensure steady progress.
Key Highlights:
• Analyzed legacy components, identified gaps, and redesigned integrations for the new system
• Developed and refactored code align the system with new integration
• Maintained clear communication with multiple teams, balancing deadlines and technical constraints
• Delivered a fully migrated solution on time, establishing a more robust foundation for future enhancements
Lead Level 3 Technical Support Engineer @ Luxoft
Mar-2013 ⟶ Aug-2015 • 2 y 6 m ( Promoted from Level 3 Technical Support Engineer in Apr-2015)
Supported a large-scale investment banking platform for a major European bank, handling dozens of application components directly and working within a global environment of numerous teams and hundreds of interconnected systems.
Responsibilities:
• Acted as deputy team lead when required during TL absence
• Managed knowledge-sharing and documentation process across distributed support teams
• Trained new employees
• Provided hands-on third-level support, going beyond simple escalations by performing deep code analysis (Java, PL/SQL, VB.NET, Perl) on applications that were often legacy and poorly documented
• Operated under high-pressure conditions, combining technical, communication, and coordination skills to quickly diagnose and resolve incidents
• Reverse-engineered complex systems to identify root causes and implement effective fixes
• Managed deployments of new builds to production
• Created documentation and knowledge base articles to improve transparency and reduce future knowledge gaps
• Collaborated closely with SL2, developers, QA, business units, and various third-party teams across multiple regions for swift, effective incident resolution
Level 2 Technical Support Engineer @ Devexperts
Oct-2011 ⟶ Mar 2013 • 1 y 6 m
24/7 support of a global FOREX trading platform
Responsibilities:
• Communicated with Level 1 engineers across regions and time zones
• Analyzed and resolved incidents and service requests; escalated to third-level support, DBAs, developers
• Did some maintenance tasks, created ad-hoc reports using SQL and PL/SQL, automated routine tasks using shell scripts
• Configured alerts, monitoring dashboards
• Monitored performance, performed sanity checks, ensured stability after releases
Education
Doctor of Philosophy (PhD) in Methods and Systems for Information Protection and Security @ Saint-Petersburg State University of Telecommunications
2011 ⟶ 2016 • 5 y
Dissertation Topic: Research and Development of Digital Steganographic Systems with Enhanced Characteristics Based on Redundant Encoding
During my research, I investigated various data hiding systems for images and proposed a novel approach that uses the generalized Viterbi algorithm to improve their robustness.
Related Publications:
1. Korzhik, V., Luna, G., & Fedyanin, I. (2015). Using the Generalised Viterbi Algorithm to Achieve a Highly Effective Stegosystem for Images. 855–860. https://doi.org/10.15439/2015F53
2. V. Korzhik & I. Fedyanin, “Steganographic applications of the nearest-neighbor approach to Kullback-Leibler divergence estimation,” 2015 Third International Conference on Digital Information, Networking, and Wireless Communications (DINWC), Moscow, Russia, 2015, pp. 133–138, https://doi.org/10.1109/DINWC.2015.7054231.
Specialist Degree in Secure Communication Systems @ Saint-Petersburg State University of Telecommunications
2006 ⟶ 2011 • 5 y
Major: Design and Development of Secure Communication Systems
I studied a wide range of subjects, including mathematics, statistics, telecommunications, physics, radio waves, standard telecommunication coding standards, information theory, programming, cryptography, and steganography (data hiding).
Thesis: Development and Study of a Digital Watermarking System for Audio Signals Based on the Use of the Echo Phenomenon
As part of my research, I developed a digital watermarking system for audio signals and optimized its parameters. I worked with MATLAB and gained expertise in signal processing, audio encoding standards, cepstrum analysis, and wet paper codes.
Related Publication:
• V. Korzhik, G. Morales-Luna, & I. Fedyanin, “The use of wet paper codes with audio watermarking based on echo hiding,” 2012 Federated Conference on Computer Science and Information Systems (FedCSIS), Wroclaw, Poland, 2012, pp. 727–732.