Yaroslav Chorniy

Employee Transportation Platform · team of 12

Built core features of a smart employee commuting platform serving 100,000+ daily commuters: real-time shuttle tracking and dynamic route optimization on a microservice architecture. Designed the ETL pipeline that syncs daily employee rosters from partner companies: mixed-format feeds mapped onto platform entities, stations geocoded by name and matched to their service area. For a rail partner it turned train timetables into trips created up to a month ahead, dispatched to the carrier and auto-cancelled when dropped from the schedule. Shipped AI features: RAG search over system-parameter docs (describe a scenario in plain language, get the parameter that controls it) and a trip assistant answering passenger and station questions from the selected trip's context. Instrumented the platform end to end with metrics, tracing and dashboards for latency, throughput and live fleet health.

• TypeScript
• React
• NX
• Recoil
• NestJS
• PostgreSQL
• Redis
• RabbitMQ
• ETL
• OpenAI API
• LangChain
• OpenTelemetry
• Prometheus
• Grafana

Cloud Point of Sale System · team of 7

Developed a cloud-based POS system for the hospitality sector: order management, inventory control and customer loyalty. Built the API entirely from scratch, including deep integration with the government tax system: each staff member generates a personal .jks key, bills are signed with it on order completion, and the encrypted signature is securely transmitted to the tax authority.

• TypeScript
• React
• Next.js
• Zustand
• NestJS
• PostgreSQL

SaaS Structured Products Platform · team of 15

Built responsive, intuitive interfaces for an investment product management platform. Designed a dynamic form engine for configuring investment products: deeply nested forms with a large number of fields governed by per-product visibility and availability rules, some shared across the product catalogue and some unique to a single product. Owned state management and ran code reviews across the frontend team.

• JavaScript
• React
• Redux
• Redux-Thunk
• MySQL
• Webpack
• Rollup

Search Engine Platform for Business · team of 10

Built the admin panel for creating search widgets, including a page exposing widget source code broken down by components: customers could add custom code, build their own widget versions, update them and view diffs between versions.

• TypeScript
• React
• Redux
• GraphQL
• Node.js
• MongoDB
• Redis
• Elasticsearch

Synthetic Monitoring · team of 3

Designed form validation logic and dynamic graph pages for monitoring website performance. Integrated Google and Facebook authentication.

• JavaScript
• React
• Redux
• Node.js
• Express
• MongoDB

E-commerce Platform · team of 5

Developed adaptive pages and custom components; set up a persistent MobX store so the discount modal never nags a user twice.

• JavaScript
• React
• MobX
• Python
• Django
• PostgreSQL

Remote Operations App · team of 10

Engineered a robust UI table widget from the ground up, efficiently handling extensive data rows for a task management product.

• TypeScript
• Angular 5
• Node.js
• Express
• PostgreSQL
• Redis

B2B Admin Platform · team of 4

Built an admin panel with dynamic form generation driven by JSON configurations.

• JavaScript
• AngularJS 1.6
• jQuery
• Python
• Django
• PostgreSQL

Taxi Application · team of 6

Developed map-driven pages with filters, Google Maps integration, WebSockets for real-time updates and Cloudinary image uploads.

• JavaScript
• AngularJS 1.5
• Node.js
• Express
• MongoDB
• WebSockets