Stanislav
From Ukraine (UTC+3)
Lemon.io stats
9
projects done3017
hours workedStanislav – Ruby, Ruby on Rails, React
Stanislav is a Ruby, Elixir, and Rust engineer who builds data-heavy backend systems. He rewrote a legal records ingestion pipeline from Ruby to Rust, cutting weekly processing from hours to 2 to 4 minutes, and now owns a manufacturing SaaS with schema-per-tenant Postgres multitenancy and LiveView-based real-time workflows.
12 years of commercial experience in
Main technologies
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Let’s get started today!Experience Highlights
Senior Full-Stack engineer
Engineering work on a security-sensitive product in the situational awareness and geospatial data processing domain, under strict NDA.
- Built backend systems for real-time geospatial data ingestion, processing, and analysis under strict correctness and reliability requirements.
- Developed functionality for digitizing field paperwork into structured, queryable data.
- Focused on predictable behavior and safe changes in a domain where data integrity directly affects operational outcomes.
Full-stack Developer
Long-term product work on a SaaS platform for managing manufacturing workflows, production stages, materials, stock, supply, and operational processes. Owned the entire technical stack: architecture, backend, frontend, database design, deployment, and production support.
- Designed and implemented PostgreSQL schema-per-tenant multitenancy with application-level tenant context switching, shared lookup tables, and tenant-scoped queries throughout the application.
- Built domain logic for the full manufacturing lifecycle: orders, products, multi-stage production workflows, stock reservations, supply item tracking, and file attachments.
- Architected the move from Rails/StimulusReflex toward Elixir/Phoenix/LiveView to leverage BEAM's multiprocess architecture for real-time production-stage tracking and interactive operator interfaces.
- Built background processing with Oban: email and messenger notifications, S3 asset lifecycle management, scheduled maintenance tasks (audit log cleanup, stale data pruning).
- Implemented data import pipelines that ingest supplier spreadsheets with inconsistent schemas, validate and normalize rows against existing inventory, and upsert into tenant-scoped tables transactionally.
- Worked across the full Elixir/Phoenix stack: LiveView for interactive UIs, Ecto for domain modeling and changesets, OTP patterns for process management, Oban for reliable job processing.
Full-stack Developer
Built and maintained a web application for collecting, analyzing, and visualizing large volumes of structured legal and regulatory records spanning decades of publicly available government data.
- Designed the full data pipeline: scheduled download of bulk XML archives from a federal data source, decompression, parsing of records, entities, and their relationships, and transactional storage into PostgreSQL.
- Rewrote the data ingestion pipeline from Ruby to Rust to solve a critical performance bottleneck — reduced weekly data processing from several hours to 2–4 minutes by parallelizing HTTP fetches, XML parsing, and batched database writes.
- Built the analytics frontend: interactive charts, filterable data tables, entity relationship diagrams, and export functionality (CSV, XLSX) for researchers.
- Implemented complex search and filtering across millions of records with PostgreSQL query optimization, partial indexes, and materialized views.
- Hired and managed a mid-level full-stack developer, coordinating work across backend and frontend tasks.
- Maintained production infrastructure: deployment, server configuration, monitoring, and reliability for a data-heavy application with large nightly query loads.
Senior Full-stack Developer
Poker training and analysis product focused on odds, probabilities, ranges, and advanced user workflows.
- Rewrote the primary application interface from jQuery/vanilla JS spaghetti into a structured React SPA with interactive charts, hand combination tables, range editors, and real-time data updates.
- Performed initial backend optimization: identified and fixed N+1 queries, added missing indexes, and simplified overly complex query paths in Rails.
- Built the data-heavy pages as a React SPA (charts, tables, hand matrices) while keeping landing, auth, and static pages as standard Rails views.
Senior Back-end Developer
Freelance backend contract on an all-in-one timesheet, absence, and payroll software product.
- .Worked as part of the backend team on API extensions and product functionality.
- Joined an existing Rails codebase and contributed quickly within established team conventions.
Senior Back-end Developer
The integrated business platform for running a profitable MSP. A mature application with a massive infrastructure and codebase.
- Backend work on a mature integrated platform for Managed Service Providers.
- Contributed across multiple teams in a large Rails codebase.
- Participated in a major version upgrade spanning application code, tests, dependencies, APIs, and backwards compatibility.
- Some exposure to Elixir/Phoenix.
Senior Back-end Developer
Financial data and analytics company providing a free trader platform, emerging manager investment opportunities, and customized software for financial institutions.
- Built backend systems, data processing, analytics features.
- Helped decompose selected monolith responsibilities into smaller services.
- Led and mentored a group of 3–5 junior/mid Ruby developers while staying hands-on with code.
Senior Back-end Developer
Plug & play solution to connect all lab instruments in a single platform. It allows collecting and analyzing instrument data in real-time and manages lab devices remotely.
- Worked on building the architecture for queueing, validating, storing, and visualizing them data.
- Used Ruby, React, RabbitMQ, and Postgres (with specific add-ons) as primary tools.