Владислав

Vladyslav Kalyna
Senior Software Engineer (Java / Kotlin)
Odessa, Ukraine | Remote English: B2+ | Ukrainian: Native
Email: [open contact info](look above in the "contact info" section) | Telegram: @Kal1naa

Professional Summary
Strong hands-on Senior Software Engineer with 6+ years of experience building scalable distributed systems.
Expert in Java and Kotlin backend development with a solid grasp of microservice architectures, reactive
programming, and modern DevOps practices. Analytical and detail-oriented, focused on delivering reliable,
high-performance systems.

Key Achievements
● Mentored 15+ students through two full Java courses, helping them reach junior developer positions.
● Re-architected a legacy system into a scalable microservice-based platform.
● Designed and deployed Kafka-based data aggregation pipelines improving data delivery speed and
reliability.

Technical Stack
Languages: Java, Kotlin, JavaScript, TypeScript, Python
Frameworks: Spring, Google Guice, Next.js, React, Redux, Material UI
Databases: PostgreSQL, MySQL, Redis, Amazon RDS, S3
Messaging: Kafka, SQS
DevOps: Docker, Maven, Gradle, AWS, Jenkins, Datadog
Other: WebFlux, Reactive Programming, Prisma, Terraform, Kubernetes, Helm

Professional Experience
Temy — Cloud E-commerce & Platform Projects
Backend / Full Stack Developer | Oct 2023 – Aug 2025
• Built a Backend-for-Frontend (BFF) layer for Android and iOS e-commerce clients.
• Integrated microservices using Feign Client to streamline communication and reduce coupling.
• Improved performance and scalability of Kotlin-based backend architecture; added contract tests for safer
releases.
• Developed a logistics data aggregation microservice consuming Kafka events, implementing schema

transformations, and optimizing
transformations, and optimizingmessage
messagehandling
handling.
(moved from former N-iX engagement).
•• Enhanced
Enhanced integrations with third-party
integrations with third-partyservices
services(Google
(GoogleMaps,
Maps,Sendgrid,
Sendgrid,Twilio)
Twilio)and
andimproved
improvedCI/CD
CI/CD
processes.
Stack: Kotlin, Java 8/11, Spring, Feign, Kafka, WebFlux, Redis, PostgreSQL, Jenkins, Docker, Keycloak,
Honeycomb, AWS, Gradle, Datadog
EPAM Systems — FinTech Platform
Key Java Developer | Mar 2021 – Oct 2023
• Refactored legacy codebase following SOLID principles to improve maintainability and delivery speed.
• Introduced caching and performance metrics to optimize data retrieval and service latency.
• Designed service structure and technical documentation; participated in code reviews and architectural

discussions.
discussions.
•• Contributed
Contributed totoCRM
CRMdata
datamigration
migration tooling
tooling andand endpoint
endpoint extensions
extensions for enterprise
for enterprise integrations.
integrations (moved
from former Digis engagement).
Stack:Java
Stack: Java11,
11,Spring,
Spring,Jetty,
Jetty,Redis,
Redis,Kafka,
Kafka,Lombok,
Lombok,Gradle,
Gradle,Datadog,
Datadog,PostgreSQL
PostgreSQL
Provectus — E-commerce
Software Engineer | Jul 2019 – Mar 2021
• Modernized legacy ticket management systems into new microservices.
• Implemented new features and improved a large-scale event ticketing architecture.
• Supported cloud-ready deployments and infrastructure automation.
Stack: Java 11, Spring Data, WebFlux, SQS, React, Redux, Docker, Kubernetes, Terraform, GitLab CI

Independent Project
Chronika (AutoTech CRM Platform) — Founder, Architect & Lead Engineer | 2025 – Present
(parallel)
• Founded and architected a digital service book and CRM platform for auto service stations.
• Built backend with Node.js / Next.js and Prisma; implemented multi-role access and service scheduling.
• Developed a React frontend (Material UI) and automation services in Python (parsing + Telegram bot).
Stack: Node.js, Next.js, Prisma, React, Material UI, Python, PostgreSQL, Docker, AWS

Education
Master’s in Software Development — Odessa National Telecommunications Academy (2022–2023)
Bachelor’s in Computer Science — Odessa National Telecommunications Academy (2020–2022)
Junior’s Degree in Software Development — Odessa College of Communication and Informatization
(2016–2020)