Looking for a job

Yurii Holubchenko

@yuriiholubchenko

Senior backend engineer, 16 years in Ruby on Rails and Python. Building APIs, data pipelines and scalable systems. Based in Spain, open to remote.

Spain

Message

What I'm looking for

I'm looking for a senior backend role in Python or Ruby on Rails, full-time and long-term, on a product with real users rather than short project work.

I'm a backend engineer with 16+ years of commercial experience and around 10 projects behind me, mostly in Ruby on Rails, and more recently in Python.

At Shopify (2021-2023) I worked in the Product & Pricing area on a platform used by millions of merchants, where correctness and performance at scale were part of everyday work.

At PreZero I was the tech lead and built the first version of their platform from scratch - choosing the architecture, setting up the foundations and leading the team through the first releases.
At Springest, an EdTech platform, I spent 2.5 years with a small team taking the product from design to a stable platform in production, owning large parts of the data layer: schema design, migrations on live data and query performance as the data grew.

Earlier I also worked on Locomote and several other products.

Since January 2026 I have been working on a Python/FastAPI project: a middleware service that integrates with external CRM API, processes the data and delivers it to internal systems. One result I'm proud of there is image upload for a single object, which went from 180 seconds down to 15. I redesigned it into parallel asynchronous uploads directly to S3 via presigned URLs, with image versioning triggered by webhook after a successful upload and a retry policy for failures.

What interests me most is backend work where design matters: clean API boundaries, data modelling, background processing and systems that keep working as the load grows. I'm actively growing in the Python ecosystem and I like to explain technical decisions to non-technical colleagues in plain words.

I'm looking for a senior backend role in Python or Ruby on Rails, remote from Spain, where I can own features end to end.

Experience

Work history, roles, and key accomplishments

Current

Backend Engineer (Python)

Current

Confidential Client

Jan 2026 - Present (9 months)

Built and maintained a production FastAPI middleware integrating a third-party service with an external CRM API, including full CRUD for scheduled and manual parsing tasks, run-session tracking, and per-task configuration. Implemented a task scheduler with APScheduler and ensured reliability through unit and integration tests.

Python fastAPI APScheduler Pytest REST APIs CRM Integration Scheduling Unit Testing Integration Testing

Senior Backend Engineer (Ruby on Rails)

Springest

Jan 2024 - Jun 2026 (2 years 5 months)

Cut bug rate from 70% to 5% over 2 years by fixing legacy issues.
Shrunk database from 550 GB to 150 GB (-73%) with a fault-tolerant cleanup system using batch deletion and retention rules.
Migrated background jobs to JobIteration with batched processing, better retries and a Redis set for failed jobs.
Built XML import pipeline with configurable VAT and pricing logic for multiple regions.

Ruby on Rails PostgreSQL

Backend Engineer (Ruby on Rails)

Shopify

Nov 2021 - Jul 2023 (1 year 8 months)

Helped launch Catalogs on Shopify's Product & Pricing team, replacing legacy price lists with region, B2B and collection-based catalogs.
Designed migration of hundreds of millions of products from price lists to catalogs via background jobs, saving critical data sync and the rest async.
Built GraphQL endpoints for catalog CRUD with frontend team.
Optimized queries and schema for Shopify scale.

Ruby on Rails GraphQL MySQL Sidekiq New Relic Redis Docker Minitest

Senior Backend Engineer (Ruby on Rails)

Registria

Sep 2020 - Oct 2021 (1 year 1 month)

Senior Backend Engineer at Registria, a warranty technology company.

Senior Backend Engineer (Ruby on Rails)

daisyBill

Sep 2019 - Aug 2020 (11 months)

Senior Backend Engineer at daisyBill, a health technology company.

Lead Engineer (Ruby on Rails)

PreZero

Sep 2018 - Aug 2019 (11 months)

Tech-led development of PreZero's first online platform from scratch, a waste management SaaS launched in 2018. Designed end-to-end system architecture including database schema, REST APIs, pricing engine, scheduling services, and admin panel, and led a team of 3 backend engineers.