Igor Khromov, Developer in Rome, Metropolitan City of Rome, Italy
Igor is available for hire
Hire Igor

Igor Khromov

Verified Expert  in Engineering

Full-stack Java Developer

Rome, Metropolitan City of Rome, Italy

Toptal member since April 21, 2014

Bio

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

Mambu
Java, React, REST APIs, MySQL, Google Cloud Platform (GCP), Docker, Kubernetes...
Menai Group
Docker, Redis, Amazon Web Services (AWS), PostgreSQL, Apache Maven, Git, Python...
Priceline
Google Cloud, Apache Kafka, Akka, Akka Streams, Kubernetes...

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

Full-time

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

2023 - 2025
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).
Technologies: Java, React, REST APIs, MySQL, Google Cloud Platform (GCP), Docker, Kubernetes, Python, Hexagonal Architecture, Apache Spark, Architecture, APIs, FastAPI, RESTFul APIs, OAuth, PySpark, API Integration

Senior Software Developer

2022 - 2022
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).
Technologies: Docker, Redis, Amazon Web Services (AWS), PostgreSQL, Apache Maven, Git, Python, Architecture, APIs, FastAPI, RESTFul APIs, JSON Web Tokens (JWT), OAuth, API Integration, Amazon RDS

Staff Software Developer

2021 - 2021
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.
Technologies: Google Cloud, Apache Kafka, Akka, Akka Streams, Kubernetes, Google Kubernetes Engine (GKE), OpenTelemetry, New Relic, Java, CQRS, Hexagonal Architecture, Test-driven Development (TDD), Agile Software Development, SQL, Jira, MacOS, IDEA IDE, Apache Maven, Python, Architecture, APIs, FastAPI, RESTFul APIs, JSON Web Tokens (JWT), API Integration, Amazon RDS

Senior Full-stack Developer

2020 - 2021
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.
Technologies: Amazon Web Services (AWS), Redux, Amazon S3 (AWS S3), PostgreSQL, Spring, React, JavaScript, Java, REST APIs, Amazon EC2, Amazon Simple Email Service (SES), Redis, Amazon API, Scrum, Agile Software Development, SQL, Jira, MacOS, IDEA IDE, Architecture, APIs, RESTFul APIs, JSON Web Tokens (JWT), OAuth, Python, Python 3, API Integration

Senior Software Developer | Team Lead | Tech Lead

2018 - 2021
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.
Technologies: Amazon Web Services (AWS), Gradle, Apache Tomcat, SOAP, REST, Spring, PostgreSQL, Oracle, Redis, Docker, RabbitMQ, Java, REST APIs, Kubernetes, Technical Leadership, Amazon EC2, Amazon Simple Email Service (SES), Amazon API, Elasticsearch, Test-driven Development (TDD), Scrum, Agile Software Development, SQL, Jira, Kanban, MacOS, IDEA IDE, Architecture, APIs, RESTFul APIs, JSON Web Tokens (JWT), Python, Python 3, Django, API Integration, Amazon RDS

Experience

Islamic Profit Sharing

https://mambu.com
Shari'ah-compliant financial calculation engine to calculate, distribute, and apply investment profits to customer accounts.
It'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.com
An online travel agency for finding discount rates for travel-related purchases such as airline tickets and hotel stays. The company facilitates the provision of travel services from its suppliers to its clients.

Goals:
• 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/
A project management tool for freelancers and business owners focuses on collaboration through digital files, including images, documents, and flat text files posted by freelancers as a result of their work.

Critical Event Communication System

https://www.onsolve.com/
Developed a critical event management communication system using emails, SMS, telephone calls, faxes, pager messages, and more. As one of the largest and most reliable critical communications providers in the world, the company combines artificial intelligence (AI), machine learning, unmatched expertise, and a modern platform.

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

2002 - 2007

Master's Degree in Software Engineering of Automated Systems

Kharkiv University of Air Forces - Kharkiv, Ukraine

Certifications

JULY 2019 - PRESENT

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)

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring