Technologies: Ruby on Rails, PostgreSQL, MySQL, Sidekiq, Solid Queue, Redis, HotWire, Stimulus, ViewComponent, Tailwind, RSpec, AWS, Linux. Some Crystal from contract work at Kagi. Claude Code daily.
Senior Ruby on Rails developer, 11+ years across fintech, SaaS, e-commerce, and startups. Open to full-time remote or contract. What I'm best at:
Performance work on existing codebases. Once optimized a set of Rails API endpoints from 90-120s down to 1-2s — measuring first, raw SQL where ActiveRecord produced bad queries, indexing, restructuring background jobs. External API integrations (5+ over my career: Google Maps, Chargebee, WhatsApp via 360dialog, SDB Groep, AFAS). Comfortable with the messy parts — retries, idempotency, webhook ordering, partial failures. Working with legacy and tests-nobody-touches. Reading before writing, refactoring without breaking things. As Tech Lead at clevergig (Dutch SaaS) for 3 years, I set up code review, bug tracking, and ownership processes for a long-lived codebase.
For fun: building a Rails app + ESP32 device that tracks power outages at my home — the device pings the API every minute, the Rails side aggregates into hours-with-power vs. without. Started during the post-2022 outages in Kyiv and kept evolving — a good way to keep Rails fresh and combine backend with a bit of hardware.
Remote: Yes (UTC+2, flexible)
Willing to relocate: No
Technologies: Ruby on Rails, PostgreSQL, MySQL, Sidekiq, Solid Queue, Redis, HotWire, Stimulus, ViewComponent, Tailwind, RSpec, AWS, Linux. Some Crystal from contract work at Kagi. Claude Code daily.
Résumé/CV: https://www.linkedin.com/in/oleksii-neishchenko-44a23893/
GitHub: https://github.com/alexneisc
Email: [email protected]
Senior Ruby on Rails developer, 11+ years across fintech, SaaS, e-commerce, and startups. Open to full-time remote or contract. What I'm best at: Performance work on existing codebases. Once optimized a set of Rails API endpoints from 90-120s down to 1-2s — measuring first, raw SQL where ActiveRecord produced bad queries, indexing, restructuring background jobs. External API integrations (5+ over my career: Google Maps, Chargebee, WhatsApp via 360dialog, SDB Groep, AFAS). Comfortable with the messy parts — retries, idempotency, webhook ordering, partial failures. Working with legacy and tests-nobody-touches. Reading before writing, refactoring without breaking things. As Tech Lead at clevergig (Dutch SaaS) for 3 years, I set up code review, bug tracking, and ownership processes for a long-lived codebase.
Recent stops: FactCTO (fintech), Rail Europe, Fitjourney.ai, Kagi (Crystal backend), clevergig (Tech Lead).
For fun: building a Rails app + ESP32 device that tracks power outages at my home — the device pings the API every minute, the Rails side aggregates into hours-with-power vs. without. Started during the post-2022 outages in Kyiv and kept evolving — a good way to keep Rails fresh and combine backend with a bit of hardware.