Eugene Ossipov, Developer in Barrie, ON, Canada
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Eugene Ossipov

Java Developer

Barrie, ON, Canada

Toptal member since November 21, 2016

Bio

Eugene has over two decades of professional experience as an architect and developer with in-depth knowledge of a wide range of methodologies and technologies. He is an expert trouble-shooter and problem solver with an extensive background in architecture, design, application development, and systems integration.

Portfolio

TD Securities
CQRS, Architecture, Domain-driven Design (DDD), Agile, Event Sourcing...
OMERS
CQRS, Event Sourcing, Kotlin, Test-driven Development (TDD), Jira, Windows...
RBC
Spring Boot, Kotlin, Jira, Windows, Linux, Spring, Agile...

Experience

  • Java - 20 years
  • Software Architecture - 20 years
  • Application Architecture - 20 years
  • Domain-driven Design (DDD) - 16 years
  • Architecture - 15 years
  • Solution Architecture - 15 years
  • Test-driven Development (TDD) - 14 years
  • Leadership - 10 years

Preferred Environment

Gradle, Git, IntelliJ IDEA, Linux

The most amazing...

...thing I have worked on is a system to evaluate the translation accuracy and for triaging claim adjudication issues.

Work Experience

Senior Software Engineer |Technical SME | Lead | Architect

2020 - PRESENT
TD Securities
  • Analyzed existing Daily Funding Requirements (DFR) System: a Net/Sharepoint application that coordinates overnight funding requests. Analyzed technical and business requirements.
  • Designed the architecture of the new generation of the DFR System. Prepared architecture blueprint and cloud profile for the system.
  • Led the development team of four DFR REST APIs, using Java 8, Spring Boot, Spring Cloud, Axon Framework, and Microsoft SQL Server.
  • Interviewed applicants for software developer positions. Mentored three intermediate developers and coops.
Technologies: CQRS, Architecture, Domain-driven Design (DDD), Agile, Event Sourcing, Functional Programming, Gradle, Git, IntelliJ IDEA, Spring Boot, Axon Framework, Microsoft SQL Server, Spring Data JPA, Liquibase, Java, TypeScript, React, Application Architecture, Software Architecture

IT Consultant | Technical SME

2019 - 2020
OMERS
  • Analyzed the existing pension administration system's (MSS) Java 6 application that manages members of the Ontario Municipal Employees Retirement System (OMERS). Analyzed the technology environment and technical and business requirements.
  • Designed the architecture of the new generation of pension administration system called Donna.
  • Created a solution prototype for membership enrollment.
  • Led the development of two services using Java 11, Kotlin, Spring Boot, Kafka, PostgreSQL, Zeebe, and Axon.
  • Interviewed applicants for software developer, DevOps, cloud architect, BA, and QA positions.
  • Mentored four intermediate, junior developers, and co-operative developers.
Technologies: CQRS, Event Sourcing, Kotlin, Test-driven Development (TDD), Jira, Windows, Linux, Spring, Agile, Domain-driven Design (DDD), Object-oriented Design (OOD), IntelliJ IDEA, JSON, Gradle, JasperReports, Functional Programming, Lambda Architecture, Architecture, Leadership, PostgreSQL, Amazon Web Services (AWS), REST APIs, Solution Architecture, Application Architecture, Software Architecture

Solution Architect

2017 - 2019
RBC
  • Defined REST API best practices to align API development across 10 teams of five to seven developers, resulting in an improved developer onboarding and client experience where every REST API followed the same principles.
  • Led the implementation of five APIs using Java 8, Kotlin, Spring Boot, Spring Cloud, Pivotal Cloud Foundry, Kafka, MongoDB, and Elasticsearch.
  • Led a team of six developers in building the Fund Accounting API completed in three months. Used by top RBC I&TS clients—ten clients generating 80% of the revenue, 1 million requests per day, resulting in the decommissioning of manual reporting.
  • Mentored four intermediate and junior developers, and as a result, three developers progressed to a senior level. All of them were able to work on critical parts of the applications.
  • Implemented a CI/CD pipeline for the APIs, using Jenkins and IBM UrbanCode Deploy.
  • Supported five APIs used by top 10 RBC I&TS clients in production; also maintained 99% SLA.
  • Interviewed applicants for software developer, BA, and QA positions, resulting in the hiring of three developers and one business analyst.
  • Spearheaded a Kotlin study group of 20 developers, resulting in adopting the new technology across three teams. The study group worked for three months.
Technologies: Spring Boot, Kotlin, Jira, Windows, Linux, Spring, Agile, Domain-driven Design (DDD), Object-oriented Design (OOD), IntelliJ IDEA, JSON, Gradle, JasperReports, Functional Programming, Lambda Architecture, Architecture, PostgreSQL, REST APIs, Solution Architecture, Confluent Kafka, Kafka Streams, Apache Kafka, Application Architecture, Software Architecture

Senior Software Developer and Architect

2015 - 2017
TD Bank
  • Created a price-supporting solution, a decision-supporting tool for issuing loans with Java 8, Spring, Hadoop, HBase, Spark, and AngularJS.
  • Developed a set of Spark jobs and web applications for loading various market data from different sources using Java 8, Spring, Hadoop, HBase, Spark, and AngularJS.
  • Developed a set of libraries and applications representing a platform for loading trade and exposure information from different sources with Java 7, Spring, and MySQL.
Technologies: JSON, Test-driven Development (TDD), Jira, Windows, Linux, Jenkins, Spring, Agile, Domain-driven Design (DDD), Object-oriented Design (OOD), IntelliJ IDEA, Gradle, Functional Programming, Lambda Architecture, Event Sourcing, CQRS, Architecture, Leadership, REST APIs, Solution Architecture, Application Architecture, Software Architecture

Senior Software Developer and Architect

2015 - 2015
TMX Group
  • Worked on a set of projects that represented a platform for over-the-counter (OTC) trades (Java 7, Apache Camel, JBoss, and MySQL).
  • Created a project-specific approach/strategy for business services communication and integration.
  • Mentored intermediate and junior developers. The developers progressed to the upper level.
Technologies: Test-driven Development (TDD), Jira, Windows, Spring, Agile, Enterprise Integration Patterns (EIP), Object-oriented Design (OOD), IntelliJ IDEA, Architecture, Solution Architecture, Application Architecture, Software Architecture

Senior Software Developer and Architect

2014 - 2015
Bank of Montreal
  • Created a Groovy-based domain-specific language for interaction with RDS servers.
  • Designed and developed a solution as a single repository for Capital Market Risk Management systems.
  • Designed and developed a utility for triggering and coordinating multiple services for Calculation Framework.
Technologies: Spring, Test-driven Development (TDD), Jira, Windows, Agile, Object-oriented Design (OOD), Architecture, Solution Architecture, Application Architecture, Software Architecture

Team Lead | Architect

2013 - 2014
The Jonah Group, Ltd.
  • Created the architecture, design, and technology principles and guidelines.
  • Wrote the software architecture document (SAD) for the NUTE project.
  • Built a technical tool to evaluate translation accuracy and triaging claim adjudication issues.
  • Led a cross-functional team of 10 people through the entire software development lifecycle for the NUTE project.
Technologies: Java Message Service (JMS), JPA, Java, Test-driven Development (TDD), Jira, Windows, Agile, Object-oriented Design (OOD), IntelliJ IDEA, Architecture, Leadership, Solution Architecture, Application Architecture, Software Architecture

Software Developer | Consultant

2009 - 2011
ParTech, Inc.
  • Designed and developed a Hazard Analysis Critical Control Point (HACCP) solution, a multi-platform IT system for managing HACCP and inspection programs for large food service organizations.
  • Worked on PDAs, sensor data acquisition, and a web-based application for the abovementioned solution.
  • Implemented three different application versions for various platforms: Windows, Windows CE, and Linux (a Java version).
  • Provided the overall guidance and structure for creating and maintaining customized solutions for Walmart, Royal Caribbean Cruise Lines (RCCL), Whole Foods, and Colorado University.
Technologies: JPA, Microsoft SQL Server, Test-driven Development (TDD), Windows, Object-oriented Design (OOD)

Software Developer | Consultant

2002 - 2009
PixelPoint
  • Designed and developed a system that allows mobile professionals to access their sites from any point in the world using the internet and remote assistance.
  • Designed and developed functionality that gathers technical and health information from the Point of Sale (POS) stations, sends alerts and notifications, controls licenses, and provides remote assistance and patch management.
  • Built a framework for integrating electronic payment solutions into the POS system.
  • Designed and implemented a security framework for the electronic payment subsystem in accordance with PCI Data Security Standards.
  • Designed and implemented frameworks for integrations of the POS with 3rd-party systems such as QuickBooks (accounting), Microsoft MapPoint, and Google Maps (mapping services).
Technologies: Java, Test-driven Development (TDD), Windows, Object-oriented Design (OOD)

Experience

Daily Funding Requirements (DFR) Platform — TD Securities

Owned end-to-end modernization of a mission-critical daily funding system. Audited the legacy .NET/SharePoint-based system, identified single points of failure, and produced the blueprint for a high-availability, low-latency microservices architecture. Architected and built the core DFR REST API engine on an asynchronous, event-driven framework (Java, Spring Boot, Spring Cloud), implementing CQRS and Event Sourcing with the Axon Framework to decouple heavy transactional mutations from real-time read projections. Led a hands-on squad of 4 engineers through deployment, code reviews, and high-throughput data processing standards, delivering the platform to production.

Kafka Streaming Performance Program — GoodLabs Studio

Acted as Kafka architect/technical SME for a production streaming data platform serving GoodLabs and its customers. Profiled complex Kafka Streams processing topologies, eliminated redundant re-partitioning, and tuned RocksDB state stores to maximize throughput and minimize latency. Designed an architectural refactoring plan resolving data skew and enforcing exactly-once processing semantics across distributed event-driven microservices. Engineered an automated performance benchmarking framework using Linux system metrics, JVM runtimes, Kafka broker logs, and Kubernetes cgroups to systematically measure lag, throughput, and resource bottlenecks. Authored a deterministic execution playbook that let development teams apply tuning updates without breaking schema compatibility or causing downtime.

"Donna" — Pension System Decomposition — OMERS

Deconstructed a monolithic J2EE (Java 6) pension administration system, isolating domain boundaries to map out a cloud-native, event-driven architecture. Engineered a production-ready solution prototype for the Membership Enrolment system with end-to-end data pipelines in Java 11 and Kotlin. Built high-throughput event microservices integrating Kafka with Zeebe and Axon to coordinate long-running distributed workflows and sagas. Optimized read/write throughput for streaming state updates using CQRS paired with heavily index-optimized PostgreSQL datastores.

Fund Accounting Streaming Pipeline — RBC I&TS

Architected and developed 5 core streaming APIs using Java 8, Kotlin, and Spring Cloud with Apache Kafka as the event backbone, processing transactional financial data across Pivotal Cloud Foundry. Engineered a mission-critical fund accounting pipeline that scaled to over 1 million real-time streaming requests per day, automating legacy manual reporting layers and saving around $100,000 CAD annually. Designed Kafka partition strategies and consumer group management to guarantee message ordering under a strict two-nines production SLA for top-tier global banking clients. Deployed automated CI/CD pipelines (Jenkins, IBM UrbanCode Deploy), enabling zero-downtime canary deployments.

Mobile Banking Microservices — Rise Financial SRL

Co-developed the core microservices architecture for a high-security mobile banking application using Kotlin, Kafka, and Spring Boot to consume real-time Open Banking APIs. Implemented event-driven Kafka pipelines processing account data streams with asynchronous synchronization into distributed MongoDB clusters. Built secure, low-latency integrations with Google Firebase to push real-time transaction states and ledger updates to the mobile client layer. Focused on high-availability state management and partition strategy optimization to prevent out-of-order execution in critical financial transactions.

Education

1989 - 1995

Master's Degree in Computer Science

State Aviation Technical University - Ufa, Russia

Certifications

APRIL 2022 - PRESENT

Kotlin Developer

JetBrains Academy

Skills

Libraries/APIs

Java Message Service (JMS), REST APIs, JasperReports, React, Liquibase

Tools

IntelliJ IDEA, Git, Gradle, Jira, Jenkins, Kafka Streams, Kafka Connect, Google Kubernetes Engine (GKE)

Languages

Kotlin, Java, TypeScript

Frameworks

Spring Boot, JPA, Spring, Axon Framework

Paradigms

Object-oriented Design (OOD), Test-driven Development (TDD), Application Architecture, Event Sourcing, Functional Programming, Lambda Architecture, Agile, CQRS, Microservices, Event-driven Design (EDD)

Storage

JSON, PostgreSQL, Microsoft SQL Server, Spring Data JPA, MongoDB, MySQL

Platforms

Windows, Linux, Amazon Web Services (AWS), Confluent Kafka, Apache Kafka, JVM, Kubernetes, Docker

Other

Domain-driven Design (DDD), Enterprise Integration Patterns (EIP), Architecture, Leadership, Solution Architecture, Software Architecture, Spring Cloud, Zeebe

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