Sergii Didenko — Senior Software Engineer

Expertise in Back-End Web (10.0 yr.), AI and Machine Learning (1.0 yr.).

Last verified on September, 2026

Core Skills

Java

8 yr.

Spring Boot

8 yr.

AI Tools & Assistants

Cursor

1 yr.

Bio Summary

Senior Software Engineer with 10+ years in cloud-native enterprise systems using Java, Spring, AWS, and Kafka.
Expertise in AI-driven production workflows, combining Python-based multi-agent systems with AWS Bedrock and retrieval-assisted generation.
Led reverse-engineering and migration of a 6-million-LOC legacy retail system to Java microservices with optimized performance.
Proficient in DevOps automation using Terraform, Helm, ArgoCD, Jenkins, and Kubernetes (EKS), enhancing CI/CD pipelines and infrastructure management.
Strong background in secure backend development, identity federation, and scalable distributed systems with domain-driven design and TDD methodologies.

Technical Skills

Programming Languages	Java, Python, TypeScript
JavaScript Frameworks	Angular, React, Vue.js
AI & Machine Learning	Cleaning Data, OpenAI, Prompt Engineering, RAG, vLLM
Java Frameworks	Hibernate, Spring Boot
Java Libraries and Tools	JPA, MyBatis, Spring Data
Data Analysis and Visualization Technologies	Apache Spark Streaming, ELT, ETL, Kafka Connect
Security	AWS Security Groups
Databases & Management Systems / ORM	Apache Spark Streaming, Firebase Realtime Database, Hibernate, IBM DB2, Liquibase, MariaDB, MongoDB, MySQL, Oracle Database, PostgreSQL
UI Frameworks, Libraries, and Browsers	Tailwind CSS
Cloud Platforms, Services & Computing	AWS
Amazon Web Services	AWS Bedrock, AWS Elastic Kubernetes Service, AWS Lambda, AWS S3, AWS SAM, AWS SDK, AWS Security Groups
Azure Cloud Services	Azure Key Vault
Google Cloud Platform	Firebase Realtime Database
SDK / API and Integrations	API, JWT, MCP, OAuth, RESTful API
Deployment, CI/CD & Administration	ArgoCD, CI/CD, GitLab CI, Gradle, Helm, Jenkins
Mail / Network Protocols / Data transfer	Consul, JWT, Traefik
Third Party Tools / IDEs / SDK / Services	Cursor
Methodologies, Paradigms and Patterns	Design patterns, microservices, microservices architecture, SOLID, TDD
Virtualization, Containers and Orchestration	Docker, Terraform
Message/Queue/Task Brokers	Kafka
Operating Systems	Linux
QA, Test Automation, Security	Reverse Engineering
Other Technical Skills	Agentic AI, Astro, Claude Code, Performance Optimization

Work Experience

Key Software Engineer, Technology R&D - Signant Health (Production AI Automation Platform and Electronic Clinician Ratings Platform)

Duration: June 2023 - Present

Summary:

Development of a production AI automation platform in Python on AWS that generates XML questionnaires/forms from source documents using specialized agents
The platform integrates LLM/agent workflows with deterministic business-rule logic and retrieval-assisted generation, supporting localization workflows
Additionally, development of workflow tooling for the Electronic Clinician Ratings platform, including a rater task queue with role-based data masking and federated identity integration across clinical platforms

Responsibilities:

Built AI automation platform combining multi-agent document processing and business logic.
Developed and deployed on AWS using Bedrock AgentCore, Strands SDK, S3, Lambda, AWS SAM, and Docker.
Created React-based web UI for the platform.
Developed workflow tooling for Electronic Clinician Ratings platform with role-based data masking.
Integrated federated identity (Exostar) and Okta synchronization across clinical platforms.
Migrated services to EKS and automated infrastructure with Terraform, Helm, ArgoCD, and Jenkins.
Led AI-assisted development adoption across the team, improving tooling usage and reducing ramp-up time.

Technologies: Python, AWS (Bedrock AgentCore, Strands SDK, S3, Lambda, AWS SAM, EKS), Docker, React, Terraform, Helm, ArgoCD, Jenkins, Exostar, Okta

Java Software Engineer, Tech Lead - EPAM Systems (Legacy RPG In-store Retail System Replatforming)

Duration: April 2019 - April 2023

Summary:

Reverse-engineering and replatforming a 6-million-LOC legacy RPG in-store retail system for Canadian Tire into a modern Java-based system
The project involved producing a documented system model, designing and implementing ETL migration mechanisms, building RESTful APIs exposing core retail capabilities, and developing replacement modules for workforce management

Responsibilities:

Reverse-engineered legacy RPG system and documented system model.
Designed and implemented ETL migration from legacy to Java platform.
Developed RESTful web-service layer exposing retail capabilities.
Optimized algorithms and workloads using profiling tools.
Developed replacement modules reverse-engineered from RPG codebase.
Acted as technical lead coordinating multiple development streams, code review, and solution design.

Technologies: Java, REST APIs, JProfiler, RPG (reverse-engineered), ETL, Microservices

Java Developer, Full Stack Developer - ReignCode SRL (Web and Mobile Platforms for Education, E-commerce, and GPS/Android Domains)

Duration: June 2015 - February 2019

Summary:

Development and maintenance of web and mobile platforms across education, e-commerce, and GPS/Android domains
Designed and launched B2B systems with secure Spring Boot backends and integrated various government APIs, payment, identity, and geolocation services
Implemented OAuth integrations and custom map features for Android and web applications

Responsibilities:

Built and maintained web and mobile platforms with broad ownership.
Designed secure Spring Boot backends with JWT authentication, Spring Security, and OAuth2.
Integrated government APIs, payment gateways, identity, and geolocation services.
Implemented OAuth integrations with Google, Facebook, and Telegram.
Developed custom map features including clustering and geofencing for Android and web apps.

Technologies: Java, Spring Boot, JWT, Spring Security, OAuth2, Google OAuth, Facebook OAuth, Telegram OAuth, Android, GPS, Geofencing, Clustering

Certification

Introduction to Claude Cowork
2026
Claude 101
2026
Claude Code in Action
2026
Introduction to Clinical Trials
2026

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