Available for opportunities

Stanislau Lisavy

Backend Developer

Building robust, scalable backend systems with clean architecture. Turning complex requirements into elegant solutions.

About Me

Passionate about building things that work at scale

Backend developer with a strong focus on building clean, maintainable, and high-performance systems. I enjoy working with distributed architectures, solving complex integration challenges, and continuously improving system design. I care deeply about code quality, testability, and delivering reliable software.

Backend Architecture

Designing resilient server-side systems with Kotlin and Spring Boot, following clean architecture principles.

Distributed Systems

Building microservice-based platforms with proper service isolation, fault tolerance, and data consistency.

System Integration

Integrating complex third-party systems — from FIX/FAST protocols to payment gateways and enterprise platforms.

Experience

Background and Key Projects

LLC Krainet

Backend Developer · July 2024 — Present

Projects under NDA — descriptions reflect general scope only

Securities Trading Platform

High-reliability platform for securities trading with real-time market data processing and order management.

KotlinJavaSpring BootPostgreSQLDocker
  • Integrated FIX/FAST protocol for real-time market data streaming with BCSE
  • Designed high-throughput REST APIs for order execution and trading workflows
  • Refactored core modules to improve scalability, latency, and fault tolerance
  • Improved system observability and reliability in a high-load trading environment

Auto-Secured Loans Platform

End-to-end loan processing platform with complex financial workflows, automated document generation and multi-system integration.

KotlinSpring BootJUnitMockitoMockKPostgreSQLDockerKeycloak
  • Architected multi-system integrations (Bitrix24 CRM, 1C via SFTP/SMB)
  • Designed automated document generation pipeline (.odt → .pdf)
  • Built microservices communication layer using REST and Kafka
  • Improved deployment workflows and environment stability
  • Engineered comprehensive unit and integration test suites (80%+ coverage)
  • Applied advanced Mockito & MockK techniques (argument captors, slots, behavioral verification) to ensure business logic reliability and edge-case resilience
  • Developed modular annuity payment calculation engine supporting multiple configurable calculators
  • Built extensible calculator framework allowing dynamic strategy resolution via factory-based orchestration
  • Encapsulated domain logic using Strategy, Composite, and Factory patterns for flexible financial calculations

Car Leasing

Enterprise-grade leasing platform with state-driven business processes and deep integration with Bitrix24 CRM for end-to-end process automation.

KotlinJavaSpring BootPostgreSQL
  • Designed and maintained deep bidirectional integration with Bitrix24 CRM, synchronizing leads, contacts, and deal lifecycle states
  • Designed and implemented complex business workflows using Spring StateMachine (states, guards, actions) to model leasing lifecycle processes
  • Encapsulated domain logic using Strategy, Composite, and Factory patterns for flexible financial calculations
  • Achieved 80%+ test coverage with comprehensive unit and integration testing
  • Applied advanced Mockito & MockK techniques (argument captors, slots, behavioral verification) to validate business state transitions and financial logic
  • Designed and implemented advanced logging pattern using BeanPostProcessor to create Proxies for put MDC

Skills

Technologies and tools I work with

Backend

KotlinJavaSpring BootREST APIgRPCFeignKafkaJUnitMockitoMockK

DevOps

DockerLinuxNginxGitGitLab CI/CD

Databases

PostgreSQLRedisSQLDatabase Design

Architecture & Principles

MicroservicesClean ArchitectureSOLIDDesign PatternsRESTTDD

Education

Academic background

Belarusian State University of Informatics and Radioelectronics

Bachelor's Degree

2022 — 2026

Languages

Communication skills

English
B2
Russian
Native
Belarusian
Native
Japanese
N5