Stanislav – Ruby, Ruby on Rails, React

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.

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.

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.

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.

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.

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.

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.

Insurance-market application with complex interconnected entities.

React frontend, then deeper Rails backend work. Optimized API performance and database queries.