11/04/2026 updated

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Lead Frontend Engineer | Angular Architecture & AI-Assisted Development

Ozarow Mazowiecki, Poland
Germany +1
info: Germany, Poland
MSc in Information Technology
Ozarow Mazowiecki, Poland
Germany +1
info: Germany, Poland
MSc in Information Technology

Profile attachments

Denys_Varlan.pdf

About me

Senior Frontend Developer / Tech Lead mit über 6 Jahren Angular-Erfahrung (Angular 8–21). Schwerpunkte: skalierbare Enterprise-SPAs, Microfrontends (Nx, Module Federation), Signals/NgRx sowie KI-gestützte Entwicklung (Claude, RAG). Erfahrung als Lead eines 4-köpfigen Teams. Sitz in Warschau.

Node.jsAngular 2+TypeScriptRxJSPlaywrightNestJS
Angular Architecture & Frontend Development
Tiefgreifende Expertise in Angular (Versionen 8-21) mit signals-first Ansatz, NgRx Signal Store, RxJS und TypeScript. Architektur und Umsetzung komplexer Enterprise-Frontend-Anwendungen in Nx-Monorepos mit bis zu 15+ Libraries.

AI-Assisted Software Development
Konzeption und Implementierung von KI-gestuetzten Entwicklungsworkflows mit Claude API, Claude Code, Codex, RAG/pgvector und agentischen Workflows. Einfuehrung von AI-assisted SDLC-Standards inklusive automatisierter Quality Gates und Code-Review-Prozesse.

Microfrontend & Monorepo-Architektur
Entwurf und Umsetzung von Microfrontend-Architekturen mit Module Federation, Nx und Web Components. Skalierung von Frontend-Systemen ueber mehrere unabhaengig deploybare Streams hinweg.

State Management
Einsatz von NgRx, Redux und Angular Signals fuer komplexes State Management in Enterprise-Applikationen mit hohem Datenfluss.

Testing & Qualitaetssicherung
Anwendung von Jest, Spectator, Cypress, Vitest und Playwright fuer Unit-, Integrations- und E2E-Tests. Einfuehrung von TDD-Praktiken und Erreichung von ca. 80% Unit-Test-Coverage.

Backend-Kenntnisse
Kenntnisse in NestJS, Node.js, .Net, MongoDB und PostgreSQL sowie Prisma ORM fuer Backend-Integration und Full-Stack-Entwicklung.

Security & Compliance
Umsetzung von OAuth 2.0, RBAC, XSS-Remediation, Angular Sanitization und Bearbeitung von Ergebnissen externer Sicherheitsaudits. Implementierung von WCAG 2.0+ Barrierefreiheitsstandards.

CI/CD & DevOps-Tools
Einrichtung und Nutzung von CI/CD-Pipelines mit Jenkins, GitHub/Bitbucket, Docker, Kubernetes und Playwright E2E im automatisierten Deployment-Prozess.

Styling & UI-Frameworks
Erfahrung mit SCSS, Angular Material, PrimeNG, Kendo, Bootstrap sowie Responsive Web Design und Mobile First Ansaetzen.

Agile Methoden & Code-Qualitaet
Arbeit nach Scrum/Agile, Clean Code Prinzipien, Code Review Prozessen und technischem Schuldenmanagement in skalierten Entwicklungsteams.

Experience

Professional experience5 - 10 years
Freelancer since2026

Languages

EnglishGoodPolishFluentRussianFluent

Project history

Lead Frontend Engineer

NEXIO (software house)
Joined as Senior Frontend Developer, promoted to Lead within 6 months. Technical & Product Owner for an AI-Assisted Developer Platform (internal product): Designed a spec-driven AI delivery workflow with ~50 custom agent skills, codified conventions and automated quality gates. Led architecture and hands-on implementation in Angular 21 (signals-first, NgRx Signal Store) in a 15+ library Nx monorepo with NestJS/PostgreSQL/Prisma backend. Built LLM-driven source-code analysis with RAG (pgvector), integrated with GitHub/Bitbucket, Jenkins CI and Microsoft Teams; set up Playwright E2E, Vitest, Docker and CI/CD. Led a team of 4 developers for a No-code Form Builder Platform over 18 months. Built an Employee Performance Evaluation System and a CMS Platform. Technical stack: Angular (19-21), TypeScript, RxJS, Nx, Jest, Spectator, AI-assisted Development (Claude, ChatGPT), Node.js, NestJs, Express, Redis, OAuth 2.0, Vitest, Playwright, PostgreSQL, Prisma, Docker.

Senior Frontend Developer

EXPLOREIT (medtech)
Contributed to Axonometric - a high-load web platform for speech therapy and patient-caregiver collaboration supporting hundreds of concurrent sessions (Angular 13+, WebSocket, RxJS). Implemented real-time session management dashboards with WebSocket communication. Participated in delivery of MediDesk - enterprise system for patient request management and business metrics (TypeScript, Nx monorepo, SASS). Worked with the UX/design team using Sketch and handled REST API integration documented via Swagger. Technical stack: Angular (13-16), React, TypeScript, RxJS, WebSocket, Nx, SASS, Swagger, OAuth 2.0.

Frontend Developer

HOGS (logistics)
Worked on an intelligent freight routing and management system built with Angular microfrontend architecture (Nx, Module Federation). Implemented Module Federation integration helping multiple frontend streams deploy independently. Built responsive UIs with PrimeNG and contributed to NgRx state management for complex data flows. Practiced TDD with Jest, helped bring unit test coverage to around 80%; also handled WebSocket communication for live freight tracking. Technical stack: Angular (10-12), Node.js, TypeScript, Nx, NgRx, PrimeNG, Jest, WebSockets, RxJS, Husky.

Frontend Developer

METAG (edtech)
Worked on a national exam management and result publication system - enterprise-grade, handling 10,000+ concurrent users at peak times. Implemented WCAG 2.0+ accessibility across assigned interfaces to meet government compliance requirements. Contributed to state management with RxJS and Redux; helped build a shared component library with Angular Material that saved the team around 20% dev time. Technical stack: Angular (8-12), TypeScript, RxJS, Redux, Angular Material, WCAG 2.0+, OAuth 2.0.

Frontend Developer

ONEXGROUP
Built e-commerce platforms, admin panels, and landing pages using JavaScript, jQuery, AJAX, Bootstrap, .Net.

Frontend Developer

LINELAB
Created advertising banners and landing pages. Gained initial experience with Gulp, JS and Bootstrap.

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