Сергій

Serhii Buniak
[відкрити контакти](див. вище в блоці «контактна інформація») | [відкрити контакти](див. вище в блоці «контактна інформація») | Ukraine, Chernivtsi

Summary

Backend Developer with experience in developing high-traffic systems and integrating third-party services. Primary focus:
.NET, microservices, and performance optimization.

Experience

Travelated | Remote
Full Stack Developer | 08/2023 - Present
I worked at a travel agency that allowed users to book a room at one of the millions of hotels listed on the website.

Main Responsibilities

Designing and documenting features (Confluence)
Coordinating decisions with the PM and Team Lead
Implementing tasks in weekly sprints with regular releases to production
Maintaining, expanding, and optimizing functionality

Key Achievements

Integrated over 10 third-party providers (REST, gRPC, GraphQL) to retrieve data on hotels, rooms, and rates
Implemented a hotel and room mapping algorithm, which increased the number of bookings by ~50%
Developed an algorithm for selecting optimal rates, reducing the user’s decision-making time by ~20%
Implemented fallback logic for invalid rates, reducing the number of failed bookings by ~40%
Integrated the Adyen payment system (Capture, Cancel, Refund, Update) and implemented webhook processing
Worked with Stripe and 3DS to improve payment stability and fraud protection
Developed an authorization microservice and integrated login via Google and Apple
Implemented the generation of hotel descriptions and tags via the ChatGPT API
Built a localization system for 15+ languages, including RTL
Created a tool for automatic localization generation (resx) using AI + DeepL.
Implemented a system for logging reservations and payments, which helped identify 3 critical bugs.
Developed a mechanism for advertising on partner sites (links and iframes)
Developed and implemented an Elasticsearch-based search engine with a response time of ~100 ms, improving user
experience and the relevance of search results.

Additionally
Fixed critical bugs in payment workflows
Helped onboard new developers
Discussed and proposed technical solutions in collaboration with the PM

Skills

ASP.NET (.NET 8), Entity Framework, PostgreSQL, Microservices, RabbitMQ, Redis, Sentry, Docker, NUnit, Moq, React,
i18next, Redux, MediatR, SignalR, REST, gRPC, GraphQL , Git, Elasticsearch

Education

Chernivtsi National University | Ukraine
Bachelor of Computer Science | 06/2024

Languages

Ukrainian - Native, English - Upper-Intermediate (B2)