Viktor Konev

Moscow, Russia

Java/Kotlin backend dev.

What I work with

Experience

Senior Developer

April 2025 – Present

RU

NDA :)

Middle+ Developer

April 2024 – April 2025

RU

Joined the team as the first engineer after the team lead, so I designed and built a large-scale product-storage system from scratch. Along the way I set up backend processes and onboarded new teammates.

Key achievements:
- Implemented product ingestion from various sources via Kafka, persisting data to a distributed Cassandra cluster.
- Built a geo-availability service that lets clients check stock in the store nearest to them.
- Squeezed maximum performance out of Postgres despite tight disk I/O limits.
- Enabled full observability for every service.

We handled high load (peaks of ~10 k RPS) with strict reliability targets. The catalog held 100 M+ products and about 300 M store-specific SKUs.

Every API shipped with clear SLOs and an internal SLA; I published metrics and set up alerts so we could catch issues early.

Middle+ Developer

November 2022 – April 2024

RU

Built microservices from scratch and drove them into production using TeamCity.

Stack: Kotlin backend with a fully reactive stack (Coroutines + WebFlux + R2DBC).

Together with the team I created a CMS for the entire insurance stream, which came with plenty of complex business logic that I both implemented and maintained.

Introduced new tools and practices to the team: JOOQ, TestContainers, WebTest (Spring MockMvc).

Also mentored incoming developers, helping them master Kotlin and the reactive stack, and guided them during their first steps on the project.

Blogs

2026-04-13

HttpClient in Spring 7: a replacement for FeignClient or not?

How to move away from FeignClient and adopt the new Spring HttpClient approach

2026-03-16

Stop Using Spring Data saveAll as a Hammer

Why saveAll(...) is often the wrong tool for bulk inserts, and how to switch to insertBatch(...).