Alexey Usov

I build systems that solve real business problems.

Backend engineer focused on payments, distributed systems and data-driven products. Turning complexity into reliable software.

Alexey Usov
Java · Kotlin · SQL
public class Developer {
  private final Passion passion;
  private final Skills skills;
  public Developer() {
    this.passion = SOLVE_PROBLEMS;
  }
  public String whatIDo() {
    return "Reliable systems. Real impact.";
  }
}

About me

I build high-load systems and solve complex business challenges. My work spans payments, integrations, logistics optimization and scalable microservices. I enjoy digging into data, understanding the domain and delivering solutions that make a real difference.

More about me
7+Years of experience
10+Payment integrations
MillionsTransactions processed
10+Countries & markets

Selected projects

View all projects
02Payment Integration Platform
JavaSpring BootKafkaPostgreSQL

Payment Integration Platform

Designed resilient payment flows, failure handling and observability for a multi-market product platform.

99.99%Service reliability
03Distributed Backend Evolution
KotlinKubernetesPulsarGrafana

Distributed Backend Evolution

Removed scaling bottlenecks and introduced a maintainable event-driven architecture for a growing product.

Traffic capacity

Tech stack

Java
Kotlin
SQL
Spring Boot
Hibernate
RxJava
Project Reactor
REST
WebSocket
Protobuf
GraphQL
PostgreSQL
MS SQL
MongoDB
Redis
Cassandra
Pulsar
Kafka
Docker
Kubernetes
VictoriaMetrics
Grafana
Prometheus
JUnit 5
Mockito
MockK
Playwright
Gradle
Maven
Jenkins
Liquibase
TypeScript
Angular
Claude Code
ChatGPT

About me

I'm a backend engineer with 7+ years of experience building software around real business problems.

My path into software engineering started with data and logistics. Early in my career, I worked with warehouse management systems, analyzed operational data with SQL, and used those insights to improve warehouse capacity and reduce storage costs. That experience shaped the way I approach engineering today: I like to understand how a business actually works before deciding what to build.

Over the years, I moved deeper into backend development and distributed systems, working with Java, Kotlin, Spring, reactive technologies, SQL and NoSQL databases, messaging systems, and Kubernetes-based environments.

For the last few years, my main focus has been payments and integrations. I've worked on 10+ payment integrations across Europe, LATAM, MENA, and Africa — from card payments and 3DS flows to mobile money and alternative payment methods. My work covers the full integration lifecycle: investigating APIs, designing solutions, communicating with external providers, implementing services, building automated and contract tests, releasing to production, and monitoring real-world behavior afterwards.

I also enjoy improving the engineering process itself. I've automated previously manual payment flows, improved integration testing, optimized CI pipelines, investigated production issues, and built tools that make complex systems easier to understand and operate.

Outside my main work, I build my own products and experiments. This gives me the opportunity to work across the whole product lifecycle — from an idea and data model to backend, UI, deployment, infrastructure, and actual users.

What interests me most is not a particular framework or programming language. It's the intersection of technology, data, and business — understanding a problem deeply and turning that understanding into a practical solution that creates measurable value.

Projects

JavaKotlinPayments3DS

Global Payment Integrations Platform

Designed and implemented 10+ payment integrations across Europe, LATAM, MENA and Africa, supporting card payments, 3DS, mobile money and alternative payment methods.

PlaywrightJUnit 5Contract Tests

Payment Integration Test Automation

Built automated end-to-end and contract testing for payment providers, including complex 3DS flows, reducing manual testing and detecting API contract changes before they reached production.

JenkinsGradleCI/CD

CI/CD Test Pipeline Optimization

Analyzed and optimized integration-test execution in Jenkins, reducing pipeline time from 21 to 16 minutes and improving developer feedback cycles.

SQLExcelWMS

Warehouse Capacity Optimization

Analyzed WMS data with SQL and built a visual warehouse utilization model in Excel to identify inefficient storage allocation, reconfigure storage cells and reduce external storage costs by approximately €22,000.

JavaSQLAnalytics

Warehouse Analytics & Visualization Tool

Extracted and transformed warehouse data using SQL and Java utilities and turned it into a visual heatmap showing storage utilization, making operational bottlenecks visible to the business.

JavaSQLCRM

Warehouse & CRM Management System

Built a custom system for managing warehouse operations, products, orders and related business processes, combining operational workflows with CRM functionality.

JavaDataMatrixPDF

Product Labeling & DataMatrix Platform

Built a full-stack system for product labeling: Excel imports, product and supply management, EPS processing, automatic label PDF generation and DataMatrix scanning with duplicate detection.

Full StackEducationWeb

Homework Management Portal

Developed a web portal for managing homework and educational workflows, bringing assignments, users and related processes into a single application.

Computer VisionAutomation

Leather Measurement Automation

Developed a computer-vision-based approach to automate leather area measurement, replacing a manual process based on physical measurement grids and improving measurement efficiency.

APIContract TestsMonitoring

Payment Provider Contract Monitoring

Created automated checks for external payment APIs to detect unexpected contract and behavior changes, reducing the risk of integration failures caused by third-party providers.

Playwright3DSE2E

3DS Browser Automation

Automated browser-based 3D Secure authentication flows with Playwright across different payment providers, replacing repetitive manual verification during integration testing.

PaymentsIntegrationsProduction

Multi-Market Payment Rollouts

Delivered payment solutions for new countries and markets by investigating local payment requirements, working directly with providers and taking integrations from API research to production monitoring.

JavaKotlinReactive

Reactive Payment Processing Services

Developed backend payment services using Java, Kotlin and reactive programming, handling asynchronous workflows and integrations in a distributed microservice environment.

GrafanaPrometheusMetrics

Production Observability for Payment Integrations

Worked with metrics, logs and monitoring to investigate production behavior after releases, identify integration problems and improve the reliability of payment flows.

LogisticsAnalysisOptimization

Logistics Service Analysis & Optimization

Investigated the algorithms and business logic behind logistics software, analyzed operational processes and translated business requirements into technical improvements.

JavaSQLAutomation

Warehouse Process Automation with Java

Built small Java-based automation tools around an existing warehouse management system to extract, process and transform operational data without modifying the core WMS.

OrdersSuppliersWorkflow

Supplier & Order Management Workflow

Designed software workflows around orders, suppliers, warehouses, payments and delivery data to simplify operational management and centralize business information.

Latest article

How I reduced payment integration testing time from 21 to 16 minutes

Playwright, 3DS automation and a smarter test flow.

Read on LinkedIn
payments.verify()
await threeDS.challenge()
tests.runParallel()

Let’s work together

Have a project in mind or just want to say hi? I’m open to interesting opportunities.

alexey.usov.job@gmail.comlinkedin.com/in/alexey-usov-job