Vitaliy

Vitaliy Kuzmich
Senior Node.js Engineer | TypeScript · NestJS · Microservices
[открыть контакты](см. выше в блоке «контактная информация»)• [открыть контакты](см. выше в блоке «контактная информация») • github.com/vitaliy-kuzmich

1,500× throughput gain · Release cycle: 2 months → 1 day · 20+ integrations unified · 12 years
of backend delivery

PROFESSIONAL SUMMARY
Node.js and TypeScript engineer with twelve years in backend development. Gets called when latency, deploy
speed or reliability has stopped being an engineering detail and become a business problem, and when a
product needs to exist within a quarter.
Real-time systems are the specialism: exchanges, market data feeds, telematics, anything with open sockets
and money moving through them. Ships the API layer, the React or Angular client above it, and the container
pipeline that deploys both.

SELECTED ACHIEVEMENTS & IMPACT
 Gained roughly 1,500× throughput on a hot execution path after redesigning it around caching,
denormalised storage and asynchronous messaging. A budgeted infrastructure upgrade was dropped.
 Cut the release cycle from two months to one day, replacing a coordination-heavy process that required
downtime with containerised CI/CD.
 Removed an entire class of production runtime errors by migrating fragile untyped code to strict
TypeScript with test coverage. Those failures now happen at build time.
 Shipped a greenfield product from blank repository to production in under three months, pulling the launch
forward by a quarter.
 Replaced dozens of one-off integrations with one reusable layer covering 20+ external services. New
partners went from weeks of work to days.
 Stabilised a legacy platform under live traffic without a single planned outage, and the emergency out-of-
hours calls stopped.
 Architected a high-load exchange so a traffic spike is answered by scaling out, not by an incident review.

TECHNICAL SKILLS
Languages: TypeScript (TS), JavaScript (ECMAScript ES6+ / ES2023, ESM and CommonJS), Node.js 18 / 20 /
22, SQL, Bash
Frameworks & Libraries: NestJS, Express.js, Fastify, Socket.IO, ws, Apollo Server (GraphQL), tRPC, BullMQ
job queues, Passport.js, Zod, class-validator, Axios, PM2, gRPC and Protocol Buffers, worker threads, streams,
clustering
ORM & Data Access: Prisma, TypeORM, Sequelize, Mongoose, Knex.js, raw SQL, migrations, transactions,
indexing, query optimisation, connection pooling
Architecture: Microservices, RESTful API design, GraphQL schema design, event-driven architecture,
message queues, Domain-Driven Design (DDD), CQRS, clean architecture, SOLID, monorepo (Nx / Turborepo),
WebSocket real-time systems, high-load and low-latency design
Databases & Messaging: PostgreSQL, MySQL, MongoDB, Redis, Elasticsearch, ClickHouse, Apache Kafka
(KafkaJS), RabbitMQ, caching strategies
Front-End: React.js 18 (Hooks, Context, Redux Toolkit, React Query), Next.js, Angular (Angular 2+, RxJS) and
AngularJS, Vue.js, modern ECMAScript, HTML5, CSS3, SASS, Bootstrap, Webpack, Vite, ESLint, Prettier,
responsive design, single-page applications (SPA), server-side rendering (SSR)
Testing & Quality: Jest, Vitest, Mocha, Chai, Supertest, Testcontainers, Selenium WebDriver, unit /
integration / end-to-end testing, TDD, SonarQube, code review
DevOps & Cloud: Docker, Docker Compose, Kubernetes (K8s), Jenkins, GitHub Actions, GitLab CI/CD, AWS
(EC2, S3, RDS, Lambda), Nginx, npm / pnpm / yarn, Git, GNU/Linux administration, structured logging, Sentry
Security: OAuth 2.0, JWT, SAML 2.0 single sign-on, session management, RBAC, rate limiting, OWASP-aware
secure coding
Also works with: Java and Spring, Go, Python on adjacent services
PROFESSIONAL EXPERIENCE

Senior Full-Stack Engineer (Node.js / TypeScript) — Purchase Order Platform
Confidential Client (NDA) · Enterprise Procurement | 10.2023 – 12.2024
 Delivered new features across a procurement platform: API services, business-rule layer, database schema
evolution and the TypeScript/JavaScript client application.
 Improved code health by decomposing monolithic modules into isolated, unit-tested services with clear
contracts.
 Partnered with product stakeholders to shape requirements and ship reviewable increments on a
predictable cadence.

Senior Engineer — Checkout & Biometric Authentication Module
Confidential Client (NDA) · Retail Technology | 01.2022 – 08.2022
 Built a fingerprint-authentication component for a retail checkout product: device communication layer,
verification service and operator UI.
 Implemented token-based auth and granular permissions to secure sensitive point-of-sale operations.
 Handled packaging, deployment, on-site debugging and client handover.

Senior Backend Engineer — Feedback SaaS Platform (Greenfield)
Confidential Client (NDA) · SaaS Product | 09.2021 – 11.2021
 Created a customer-feedback service from scratch: domain modelling, REST API design, persistence layer,
background jobs and release pipeline.
 Owned technology selection and shipped a production-ready MVP within a fixed deadline.

Senior Full-Stack Engineer — Fleet Management System
Confidential Client (NDA) · Logistics & Transportation | 07.2021 – 01.2022
 Maintained and incrementally modernised a large legacy fleet-tracking platform without downtime for
active users.
 Resolved production issues around concurrency, data consistency and third-party telematics APIs.
 Shipped both server-side fixes and JavaScript/Angular front-end improvements as the module's sole owner.

Senior Engineer — Healthcare ERP & Cloud Analytics Service
Confidential Client (NDA) · Healthcare & Cloud | 09.2020 – 04.2021
 Developed new modules and fixed defects in a production ERP handling sensitive patient and billing data.
 Delivered a cloud analytics service on ClickHouse for high-volume reporting queries.
 Optimised data-access paths and caching to accelerate the platform's heaviest screens.

Senior Full-Stack Engineer / DevOps — Developer Tooling Platform
Confidential Client (NDA) · Atlassian Ecosystem | 12.2019 – 06.2021
 Implemented core plugin components from scratch, integrating a third-party platform API with internal
enterprise services.
 Owned the full DevOps chain: Docker, Jenkins CI/CD, environment provisioning and automated releases.
 Acted as messaging subject-matter expert on a parallel engagement, tuning queue-based integration flows
for reliability and throughput.

Software Architect & Lead Developer — High-Load Cryptocurrency Exchange
Confidential Client (NDA) · FinTech / Trading | 03.2018 – 06.2018
 Designed the microservice architecture for a high-load exchange: order pipeline, denormalised data model,
Redis caching and asynchronous message bus.
 Defined horizontal scaling, fault isolation and consistency strategies for concurrent trading workloads.
 Led technical decision-making and reviewed performance-critical code paths.

Node.js & Web3 Engineer / Consultant — DApp and Blockchain Products
Confidential Clients (NDA) · Blockchain / FinTech | 08.2017 – 06.2018
 Built a sports-betting decentralised application: Node.js backend services, a Web3 JavaScript integration
layer and the browser client on top.
 Delivered token and crowdsale products, including scheduled workflows driven by external oracle services.
 Advised clients on architecture, technical feasibility and delivery planning, and authored supporting
technical documentation.

Full-Stack Engineer & Linux Administrator — Integration Library, Risk Platform, ERP
Confidential Clients (NDA) · Enterprise & FinTech | 01.2015 – 05.2017
  Architected a concurrent integration library connecting a large enterprise system with 20+ external
services and protocols.
 Built a clustered financial risk-calculation web application, owning both computation backend and browser
front-end.
 Delivered an ERP platform from scratch and operated its production Linux infrastructure (Nginx, application
servers, mail, DNS).

Software Engineer — Trading Platform, Real-Time Clients and Telematics
Confidential Clients (NDA) · Trading & IoT | 04.2013 – 09.2015
 Developed back-office modules, order processing, reporting and data-access layers for a clustered trading
broker platform.
 Built real-time clients streaming live market and GPS data over WebSocket and custom binary protocols.
 Integrated IoT devices with backend tracking services and REST APIs.

OPEN-SOURCE & PERSONAL ENGINEERING PROJECTS
github.com/vitaliy-kuzmich/bets — Sports-betting decentralised application with a Node.js backend and
JavaScript client integration layer.
Self-hosted cloud storage server — Author of an open-source Nextcloud alternative for low-resource
hardware, with a JavaScript SPA front-end.
Upstream contribution — Reported and fixed a defect in a widely used open-source security framework.

EDUCATION & PROFESSIONAL DEVELOPMENT
Master of Science, Information Security Engineering — University of Technology, Dnipro, 2007 – 2012
Professional Software Engineering Program (certified) — SoftServe, 2012

ADDITIONAL INFORMATION
Languages: English — professional working proficiency; Ukrainian — native; Russian — native
Work Style: Remote-first, distributed and cross-functional teams, Agile / Scrum / Kanban, code review
culture, mentoring of mid-level and junior engineers
Interests: Cycling, hiking, strength and endurance training, embedded electronics, open-source contribution