
Igor Khromov
Verified Expert in Engineering
Full-stack Java Developer
Rome, Metropolitan City of Rome, Italy
Toptal member since April 21, 2014
Igor is a senior software engineer with experience in enterprise back-end development. He has also received a Master's degree in computer science and has spent more than 12 years to learn in depth the best software development practices. Igor is a reliable and responsible individual who has been working remotely as an independent professional for the US and EMEA regions.
Portfolio
Experience
- Java - 9 years
- PostgreSQL - 8 years
- REST APIs - 8 years
- Python - 6 years
- Architecture - 6 years
- Technical Leadership - 5 years
- Amazon Web Services (AWS) - 5 years
- Kubernetes - 2 years
Availability
Preferred Environment
MacOS, Linux, Terminal, Bash Script, PyCharm, Visual Studio Code (VS Code), IntelliJ IDEA
The most amazing...
...thing I've built is a real‑time air-defense simulator of aerial threats to train military commanders.
Work Experience
Senior Full-stack Developer
Mambu
- Designed architecture components for a profit-sharing calculation engine used by more than 200 customers in Islamic countries.
- Engineered a real-time data pipeline using Kafka and Debezium with MySQL, calculating account balances across microservices for 20+ million users.
- Orchestrated secure microservices authentication/authorization for a core banking engine (monolith) via AWS Gateway and Kubernetes, fortifying system defenses against potential breaches.
- Created over 200 tests, including unit (JUnit, Mockito), integration, business (JBehave), and end-to-end tests (Playwright).
Senior Software Developer
Menai Group
- Designed and implemented REST API/WebSocket high-performance connectors for fetching data from 30+ crypto exchanges and trading platforms.
- Designed universal adapters to unify trading data needed for back-office ETL pipelines (P&L, positions, etc.).
- Pioneered a fully automated CI/CD pipeline that enabled the deployment of vendor connectors to different staging environments, reducing manual intervention by 85%.
- Orchestrated the creation of microservices for live trading data collection, processing, and storage, using NATS message queues for efficient data delivery and processing, reducing latency by 60% (compared to Kafka).
Staff Software Developer
Priceline
- Designed and developed a microservice for real-time request aggregation with Akka and Kafka to 3rd-party data suppliers (global distribution system), allowing the company to save USD 250,000 yearly for API consumption budget.
- Fortified application resilience by configuring alerts on Micrometer-exposed metrics, resulting in a 30% reduction in critical incident severity, enabling quicker incident response and minimizing system downtime.
- Initiated OpenTelemetry integration for end-to-end tracing, boosting system visibility and enabling the team to identify and mitigate three of the biggest causes of issues and performance bottlenecks.
- Created 100+ unit (JUnit, Mockito) and integration tests (Testcontainers) for a microservice, achieving over 90% code coverage.
Senior Full-stack Developer
Pantram
- Orchestrated the architecture for a project management system from scratch, streamlining workflows for 200+ users and leading to recognition as 'Most Innovative Solution' at company awards.
- Designed and implemented 5+ microservices for authentication/authorization, file storage on cloud providers (Amazon S3), user notification on iOS/Android, running email marketing campaigns, and REST API services for a React UI application.
- Built UI user and administration websites with React and Redux, which served over 5,000 users in the first month.
Senior Software Developer | Team Lead | Tech Lead
DataArt
- Spearheaded the transformation of a monolithic system into a 10+ microservices architecture in 12 months to reach a goal of zero-downtime deployments.
- Automated deployment processes for 10+ microservices using Kubernetes and a configuration as code approach, decreasing deployment time by 60% and allowing for a faster release of new features to production.
- Developed a high-load testing framework with Testcontainers and MockServer to emulate intensive load during business hot hours, which allowed more than 80% of problems to be caught before microservices were deployed to production.
- Created more than 300 unit, integration tests (Testcontainers, MockServer) to reach test coverage of 90+% for each microservice.
- Led and mentored a team of eight developers, fostering a culture of continuous learning and self-improvement as an engineer, resulting in 100% of team members reaching the next grade level within the next year after joining the team.
- Conducted over 100 personal technical interviews to create a very strong and result-oriented team for developing the customer's core product.
Experience
Islamic Profit Sharing
https://mambu.comIt's built as part of Mambu's advanced cloud-native banking technology. This flexible, composable platform allows for the development and launch of investment products for Islamic countries.
High-performance Service for Request Aggregation to Global Distribution System (GDS)
https://priceline.comGoals:
• Develop high-performance microservice built on hexagonal architecture.
• Create an Akka Stream pipeline to consume, process, and produce Apache Kafka messages.
• Create logging, tracing, and metrics configs to integrate with NewRelic.
• Write unit integration tests to cover the most important parts of the application logic.
Design Project Management System from Scratch
https://cieden.com/Critical Event Communication System
https://www.onsolve.com/Goals:
• Apply requirements developed by the US Government for Securing Cloud Services (FedRAMP).
• Split big monolithic applications into microservices.
• Create microservice integrations with queues, files, and databases.
• Create a deployment flow with Docker and Kubernetes.
• Create Selenium tests.
• Create unit tests.
• Create integration tests with Testcontainers.
• Interviewed new team members, junior or middle-level members mentoring.
• Backlog management.
Education
Master's Degree in Software Engineering of Automated Systems
Kharkiv University of Air Forces - Kharkiv, Ukraine
Certifications
Oracle Certified Associate, Java SE 8 Programmer
Oracle
Skills
Libraries/APIs
REST APIs, Flexbox, Amazon API, Liquibase, PySpark, React, Akka Streams
Tools
IDEA IDE, Sublime Text, Amazon Simple Email Service (SES), Git, Jira, PyCharm, NGINX, TeamCity, DataGrip, Terminal, Apache Maven, Jenkins, Apache Tomcat, Gradle, RabbitMQ, Subversion (SVN), Google Kubernetes Engine (GKE), IntelliJ IDEA
Languages
Java, JavaScript, TypeScript, SQL, Python, Python 3, Bash Script
Frameworks
Spring, Redux, Spring MVC, Spring Boot, JSON Web Tokens (JWT), Django, Hibernate, Akka, Spring Security, Apache Spark
Paradigms
Microservices, Kanban, Agile Software Development, Scrum, Test-driven Development (TDD), REST, CQRS
Storage
PostgreSQL, MySQL, Amazon S3 (AWS S3), Elasticsearch, MongoDB, Redis, Google Cloud
Platforms
Docker, Amazon EC2, Amazon Web Services (AWS), MacOS, Unix, Visual Studio Code (VS Code), Oracle, Kubernetes, FreeBSD, Apache Kafka, New Relic, Linux, Google Cloud Platform (GCP), Azure
Other
Technical Leadership, APIs, RESTFul APIs, API Integration, Hexagonal Architecture, Architecture, FastAPI, OAuth, Software, Engineering, Amazon RDS, Openfire, Natural Language Processing (NLP), SOAP, Java 17, OpenTelemetry, Apache Cassandra, Shell Commands, Generative Pre-trained Transformers (GPT)
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