Владислав

Vladyslav Buhai
Phone: [open contact info](look above in the "contact info" section)
Email: [open contact info](look above in the "contact info" section)
LinkedIn: [open contact info](look above in the "contact info" section)
Location: Ukraine

BACKEND SOFTWARE ENGINEER - FINTECH FOCUSED

- Backend Software Engineer with 5 years experience, currently Team Lead at fintech startup
- Building reliable, scalable payment infrastructure — from gateway integrations to transaction processing —
using Kotlin/Spring Boot and event-driven architectures.
- Strong foundation in Kotlin/Spring Boot (2+ years) and Node.js/NestJS (3 years); transitioned to Kotlin in
2024 to deepen backend expertise in FinTech.
- Led team of 3 engineers; own production deployments, code quality, and operational excellence
- Pursuing PhD in Computer Engineering (2022-present)

TECH STACK

Core: Additional:
Kotlin Mockito Maven Grafana Socket.IO React TypeORM
Spring Framework Kubernetes Docker CloudWatch MongoDB Node.js Prisma
PostgreSQL Docker RabbitMQ TypeScript NestJS
JUnit Kafka S3

PROFESSIONAL EXPERIENCE
Exirom | Remote Sep 2024 - Present
Software Engineer → Team Lead Software Engineer
Leadership & Team Development (from Aug 2025)
Lead engineering team of 3: conduct 1-on-1s, set technical direction, coordinate sprint planning.
Mentor 2 junior engineers through pair programming and structured feedback sessions
Established code review standards and quality gates, improving deployment confidence and reducing
production incidents by 25% through e2e testing service
Technical Architecture & System Design (from Sep 2024)
Developed and supported distributed payment gateway system processing 1M + monthly transactions
with 99.9% uptime, handling card payments and alternative payment methods (APMs) across multiple
PSPs
Programmed event-driven architecture using Kafka for asynchronous transaction processing,
implementing retry mechanisms with exponential backoff, dead-letter queues and idempotency
guarantees for high-availability
Integrated 15+ external payment service providers (under NDA) with distributed cascading, ensuring data
consistency across distributed transaction flows and handling failure scenarios
Operational Excellence & Production Ownership (from Sep 2024)
Implemented end-to-end observability stack integrating CloudWatch, Prometheus, and Grafana with 24/7
alerting infrastructure, enabling proactive detection of PSP incidents (in several cases identifying
provider-side issues before official notifications)
Own production deployments and release coordination: manage CI/CD pipelines (GitHub Actions →
AWS), monitor rollouts, coordinate rollback procedures when needed
Lead incident response lifecycle: conduct root-cause analysis and post-mortems for 3 production issues
Built internal FX/exchange-rate service with caching and automated update mechanisms, supporting
multi-currency transaction processing
Ensured system reliability through comprehensive test coverage: unit tests (MockK) and integration tests
(Testcontainers)
Exirom | Remote Jun 2024 - Sep 2024
Full Stack Engineer
Led backend API migration from JavaScript to TypeScript across core modules, improving type safety
and code reliability, establishing foundation for team's transition to typed languages
Designed and implemented asynchronous report generation service with S3 integration and background
job processing, significantly reducing generation time and improving user experience
Refactored and stabilized legacy payment processing modules, eliminating technical debt and improving
test coverage to enable safer feature development
Optimized transaction monitoring backend: improved API response times through query optimization and
caching strategies, supporting real-time dashboard performance

DevIT | Remote Feb 2023 - Jun 2024
Full Stack Engineer

Developed backend services using Node.js/NestJS for construction carbon-emissions calculation
platform, optimizing calculation workflows and automating tax report generation
Built Bill of Quantities (BOQ) platform backend. Designed PostgreSQL data models, implemented RESTful
APIs for multi-level custom reporting and automated cost estimation for construction projects
Optimized website backend performance through simplifying the component structure and optimizing
GraphQL-based API requests.
Provided technical estimates and delivery planning for cross-functional projects: scope definition,
timeline assessment, risk identification

Techstack Ltd | Hybrid Jun 2021 - Dec 2022
Software Engineer

Designed data models and implemented RESTful APIs using Node.js/Express for training sandbox
platform and career portal
Migrated company blog to Next.js with server-side rendering, improving site performance and SEO
rankings
Developed task management platform for design agencies: brief creation workflows, version control and
project collaboration features

EDUCATION
Phd of Computer Engineering
National Technical University «Kharkiv Polytechnic Institute»
2022 – Present
Majors: Modern Programming, Mobile Devices and computer Games

Master degree of Computer Engineering
National Technical University «Kharkiv Polytechnic Institute»
2020 – 2021
Majors: Modern Programming, Mobile Devices and computer Games
Additional information: Diploma with honors

Bachelor degree of Computer Engineering
National Technical University «Kharkiv Polytechnic Institute»
2016 – 2020
Majors: Modern Programming, Mobile Devices and computer Games

CERTIFICATION
AWS Certified Cloud Practitioner
Udemy
In progress

LANGUAGES
English - Upper Intermediate
Ukrainiane - Native