Location: Bucharest, Romania (relocating to Lisbon, Portugal in November) Remote: Yes (remote only) Willing to relocate: Already relocating to Portugal in November — no further relocation Technologies: Ruby, Rails, PostgreSQL (partitioning, query/performance tuning), OpenSearch/Elasticsearch, Kafka, Sidekiq, Redis, pgvector/RAG, Docker Résumé/CV: https://docs.google.com/document/d/1tR_dLSXezY31gFgmA_BUTWDL... Email: savenko.sy@gmail.com

Senior Ruby/Rails engineer, 11+ years. My specialty is data-heavy Rails: making it fast, and making it correct.

- Partitioned PostgreSQL at scale — ~330M rows / ~220GB in production, entity resolution and duplicate-merging across 100M+ row tables - Query performance — 5–40x speedups by restructuring schemas and moving hot paths off Postgres onto OpenSearch - Billing engines — rebuilt one for ~10x faster calculation and ~50% smaller database (ActiveRecord→ROM), another for a 5x speedup on the bill pipeline - Recently — pgvector/RAG inside Postgres, LLM integration in Rails (RubyLLM, MCP tooling)

Likely a good fit if you have a Rails app outgrowing its database, a billing or usage-metering system that's slow or subtly wrong, or you want RAG without bolting on a separate vector DB.

Open to full-time or contract. 4+ hours of daily overlap with US East now; the Lisbon move in November adds 2 more. I invoice through a registered sole proprietorship with a W-8BEN on file — no US withholding under the treaty, nothing for a finance team to set up.