Владислав

VLADYSLAV BOHOLII Email: [open contact info](look above in the "contact info" section)
Github: github.com/hronograf
Java Developer LinkedIn: [open contact info](look above in the "contact info" section)

SKILLS
Core: design of web applications and relational databases, feature ownership from investigation and planning to
release, optimization of application performance.​
Technologies: Java, Spring Boot, Hibernate, PostgreSQL, JavaScript, HTML, CSS, Angular,​
AWS (Lambda, SQS, S3), JMeter (load testing), Redis, GraphQL, Git, Docker.

EXPERIENCE
Kyivstar.Tech | Adwisor Jun 2024 – Present
●​ Built and owned backend features across the full promo-campaign lifecycle: audience preparation,
campaign triggering and reporting
●​ Led a service refactor that split a single webhook-processing service into several business-group
microservices (same codebase, separate deployments and queues), enabling targeted scaling and
isolation for critical message types (transactional API)
●​ Reduced delayed webhook deliveries (>30s) for transactional messages from 60,000+ per day to <1,000,
while operating a system processing 5M+ messages daily, including 2M+ transactional messages and peak
loads of 300k+ transactional messages/hour.
●​ Contributed to the development of a microservice that builds campaign audiences by selecting user
subsets according to complex demographic constraints defined by clients (e.g., gender ratios and
age-group distributions).
●​ Actively contributed to system design discussions, feature planning, and implementation strategy,
proposing solutions that improved user experience and simplified engineering implementation.
●​ Owned production stability for developed features: investigated and fixed production incidents, contributed
hotfixes and follow-up improvements.

Mate academy | Cusbo Aug 2022 – Feb 2024
●​ Configured integration tests from scratch to test interactions with AWS OpenSearch using​
JUnit test containers. Designed a test hierarchy that helped to write clean tests.
●​ Implemented integration with Shopify on my own - from tech doc to listing on the app store, which opened
a new marketplace for our platform.
●​ Added analytics to the platform. Complex SQL queries were optimized by refactoring and adding indexes.
Execution time for one of the queries was reduced from 10-20+ seconds to 5-10 milliseconds​
for 1 500 000+ rows on staging DB.
●​ Reduced execution time of most frequent http requests by 20%, improved max system load ​
from 100 requests/minute to 500 requests/minute for such requests.
●​ Was an on-duty person, ensured stability of the product by checking metrics in AWS and managing
rollbacks and hot-fixes in critical scenarios.
●​ Implemented functionality that allows to enable features for certain companies, which protected the main
part of our clients from bugs found during the preview phase.
●​ Participated in adding billing, mobile adaptation, mail integration, and other features.
●​ Managed a team of 6 mentors, conducted 20+ tech interviews, and made final decisions about hiring for 5+
mentors.
Microcredit company Aug 2021 – Aug 2022
●​ Implemented complex SQL queries that were used to find issues in user flow, analyse company’s finances.
●​ Was responsible for making changes in user flow business logic.
●​ Found insights in data that improved the accuracy of ML models by 10-20%.

SCIENTIFIC WORKS
Fraud detection system for Spring framework with elements of machine learning May 2021
A system that recognizes anomalies in requests to an application and detects XSS and SQL injections by using the
fastText model.

EDUCATION
Bachelor of Computer Science
National University of Kyiv-Mohyla Academy Sep 2018 – Jun 2022
Architecture of highly loaded systems: lab, basics of high load apps (queues, caching, scalability, db sharding)
Web application security: SQL-injections, XSS, CSRF, RCE, Business logic vulnerabilities, Insecure deserialization
Spring Boot: final project (designed API and business logic security, designed database schema and optimized DB
requests, performed code review), labs, unit and integration testing, REST testing, Hibernate, JPQL, JpaRepository,
Spring Boot Starters and other
Basics of artificial intelligence: AI-checkers bot based on minimax algorithm with heuristic which has been found
by genetic algorithm (1st place in the tournament), simple phatic dialogue bot, genetic algorithms, search agent