ROGER MESTANZA MARTINEZ

Front-End Software Engineer

Software Engineer specialized in Front-End development, with 3+ years of experience building scalable web applications: B2B SaaS platforms, e-commerce, and real-time AI agent systems. Advanced proficiency in Angular 20+ and React 19+, component-based architectures (DDD, Clean Architecture), complex state management (NgRx, Zustand), and web application security (OAuth 2.0, JWT, RBAC). Committed to clean code, SOLID principles, and delivering high-impact technical solutions in agile, production-grade environments.

rogers.mestanza@gmail.com+51 913 346 942Lima, PeruLinkedInGitHubGitLab

Skills

JavaScriptTypeScriptNode.jsHTML5CSS3Angular 20+React 19+NgRxRxJSHooksTailwind CSS v4ZustandImmerDaisyUIShadcnUISASSViteEChartsWeb ComponentsShadow DOMDomain-Driven DesignSPAMicro FrontendsSSRAtomic DesignComponent-BasedFlux/ReduxClean ArchitectureLayered ArchitecturePorts & AdaptersRepositoryFacadeStrategyObserverFactoryBuilderSingletonDecoratorMediatorStateCQRSJestKarmaVitestJasmineDockerCI/CDAWS ServicesFigmaPostmanChrome DevToolsVS CodeGitGitHubCursorClaude CodeClean CodeSOLIDRefactoringBig-O analysisdata structuresalgorithms

Experience

Front-End Developer

Konstrutecnia (Wirana.ai B2B SaaS platform)

2025-07 – Present

  • Led front-end development for two products within the Wirana.ai B2B SaaS platform, which powers AI agents that autonomously engage customers and close sales across multiple channels (WhatsApp, email, Shopify, WooCommerce).
  • Built the KT Agents Dashboard with Angular 20 and NgRx 20 under a Domain-Driven architecture (14 lazy- loaded domains, 2,000+ TypeScript files, 294 components), reducing initial load time by ~25-30% through domain-based lazy loading.
  • Developed the Wirana Support Widget, an embeddable Web Component (<kt-widget>) built with React 19, Zustand + Immer, and isolated Shadow DOM, shipped as an IIFE + ESM bundle (<50kb gzipped), integrable into any website with just 2 lines of code.
  • Implemented real-time streaming of AI agent responses via WebSockets with automatic reconnection (exponential backoff) across both products, improving session continuity and reducing perceived latency in end-user conversations.
  • Applied Clean Architecture + DDD principles to the Widget (5 layers: domain, application, infrastructure, presentation, cross-cutting) with 56 domain entities and zero circular dependencies, validated with dependency-cruiser.
  • Designed a granular RBAC system (5 permission levels) integrated with NgRx, a PermissionGuard, and a *appHasPermission directive, alongside a 5-step HTTP interceptor pipeline (camelCase↔snake_case transformation, JWT handling, centralized error handling).
  • Integrated OAuth 2.0 with Shopify and WooCommerce, multi-language support (ES/EN/PT) with Transloco, an in-house 41-component UI library (Tailwind CSS v4 + DaisyUI v5), and 3 testing layers: unit (Vitest/Jasmine), E2E (Playwright), and architecture validation.

Freelance Developer

Independent Projects (independent clients)

2023-02 – 2025-06

  • Designed and developed multiple web projects for independent clients, ranging from landing pages to complex dashboards with payment gateways, admin panels, and intranets with user and role management.
  • Broadened technical versatility by building full-stack personal projects (backend integrations, databases, and payment gateways) and small C++ and Java projects, including video games, delivered to freelance clients.
  • Pursued intensive self-directed training through OpenBootcamp, FreeCodeCamp, Coursera, and Alura Latam, focused on web development, building a strong foundation in JavaScript, Java, C++, Node.js, TypeScript, Python, and more, along with software engineering best practices.
  • Full project details for this period are available on my GitHub profile (linked in header).

Front-End Developer

Henry Bootcamp

2022-07 – 2023-01

  • Designed and structured the system architecture using a layered architecture approach, applying principles of scalability, modularity, and maintainability.
  • Contributed to the initial System Design planning for the project, comprising 200+ components including buttons, modals, cards, dialogs, tabs, and more.
  • Designed and developed dynamic, responsive interfaces with React.js, Redux, and Hooks, improving user experience by ~20-30%.
  • Implemented modular design with CSS3, SASS, Tailwind CSS, and Webpack to optimize load performance, maintain consistent component styling, and ensure reusability of modular components.
  • Integrated RESTful and GraphQL APIs for consuming external data, improving view interactivity and responsiveness.
  • Applied TDD practices with Jest and React Testing Library, ensuring component stability and code quality.
  • Collaborated closely with the backend team on business logic and architectural decisions throughout the project.
  • Developed the project using Git version control with GitHub to support effective teamwork.
  • Automated CI/CD deployment using tools such as Docker, GitHub Actions, Netlify, Heroku, and AWS services including Amazon S3.
  • Participated in agile teams under the Scrum methodology.

Projects

◆

WhiteSide Storage App

Electronic device management platform built with Angular 18+, NgRx, HTTP interceptors, JWT, OAuth 2.0, and Stripe. Tested with Jest and Karma.

◈

Color Organizer App

Color palette management application with Angular, NgRx, RxJS, Reactive Forms, Lazy Loading, and Firebase Authentication. Custom directives and pipes.

◈

Webpack + TS + Babel + SASS Template

Optimized web template published on npmjs.org with TypeScript, SASS, HMR, and Jest support for scalable rapid prototyping.

◈

UI/UX Optimization

Refactored internal platform applying Lazy Loading and Code Splitting, improving Lighthouse metrics and responsive design.

Education

Universidad Tecnológica del Perú

Certifications

  • Front-End Developer, Alura (2023)
  • Full Stack Developer, Henry Bootcamp (2023)
  • Web Application Development, MTPE (2024)
  • Mobile Application Development, FreeCodeCamp – OpenBootcamp (2024)
  • Cisco Networking, Cisco (2025)
  • Front-End Web Developer, Wirana.ai (2026)

Career highlights

July 2025

  • Started: Front-End Developer at Konstrutecnia (Wirana.ai B2B SaaS platform)

    Konstrutecnia (Wirana.ai B2B SaaS platform)

February 2023

  • Started: Freelance Developer at Independent Projects (independent clients)

    Independent Projects (independent clients)

July 2022

  • Started: Front-End Developer at Henry Bootcamp

    Henry Bootcamp

Built with Round Zero