Senior React Developer

Company Overview:
Lean Tech is a rapidly expanding organization situated in Medellín, Colombia. We pride ourselves on possessing one of the most influential networks within software development and IT services for the entertainment, financial, and logistics sectors. Our corporate projections offer many opportunities for professionals to elevate their careers and experience substantial growth. Joining our team means engaging with expansive engineering teams across Latin America and the United States, contributing to cutting edge developments in multiple industries.

Position Title: Senior React Developer

Location: Remote (LATAM)

What you will be doing:
We are seeking a proactive and skilled Senior React Developer with 5+ years of professional experience building high-performance, scalable web applications using modern React standards. This role involves leading architectural decisions, mentoring other developers, and collaborating closely across teams to deliver high-quality, maintainable software solutions. A strong understanding of performance optimization, testing strategies, accessibility, and modern front-end tooling is key. You'll leverage AI powered development tools to accelerate delivery, improve code quality, and enhance user experiences.
● Develop and implement new user-facing features using React Hooks, Context API, 
and modern JavaScript (ES6+).
● Build reusable and scalable components and libraries with strong documentation and test coverage.
● Optimize performance using techniques like , useMemo, and use Callback; apply code splitting, lazy loading, and bundle analysis for fast, efficient UIs.
● Ensure Core Web Vitals and Lighthouse performance metrics meet high standards.
● Integrate with REST and GraphQL APIs, including payment and third-party services.
● Implement unit, integration, and end-to-end testing (Jest, React Testing Library, Cypress).
● Apply TDD principles and ensure high test coverage.
● Lead by example through code reviews, mentorship, and fostering engineering best practices.
● Collaborate with UX/UI, QA, and backend teams under Agile/Scrum methodologies.
● Champion accessibility (WCAG 2.1) and semantic HTML practices.
● Contribute to technical documentation, including Storybook, design docs, and ADRs.
● Maintain strong security practices, addressing XSS, CSRF, and authentication patterns (OAuth/JWT).
● Participate in system design discussions, scalability planning, and architectural decision-making.

Requirements & Qualifications:
To excel in this role, you should possess:
● 5+ years of experience in React and JavaScript (ES6+) development.
● Advanced knowledge of React performance optimization and state management (Redux Toolkit, Zustand, or Jotai).
● Experience with or similar SSR/SSG frameworks.
● Proficiency with modern styling solutions (CSS-in-JS, Tailwind, CSS Modules).
● Experience with CI/CD pipelines and build tools (Vite, Webpack, esbuild).
● Familiarity with containerization (Docker) and micro-frontend architectures.
● Experience integrating AI-assisted tools like GitHub Copilot or ChatGPT into daily workflows.
● Solid understanding of cross-browser compatibility, PWA development, and web performance monitoring tools (Sentry, LogRocket).
● Proven experience with component architecture design patterns (Compound Components, HOCs, Render Props).

Nice to have:
● Experience with GraphQL client libraries (Apollo, urql, Relay).
● Exposure to monorepo tools (Nx, Turborepo).
● Prior experience contributing to or maintaining design systems.
● Knowledge of micro-frontend or modular architecture.
● Familiarity with AI/ML-based front-end tooling for automation or optimization.

Soft Skills:
● Strong written and spoken English communication (B2+ level).
● Leadership and mentorship mindset, fostering continuous learning.
● Collaborative and adaptable with strong problem-solving abilities.
● Detail-oriented, proactive, and capable of managing multiple priorities.

Why you will love Lean Tech:
● Join a powerful tech workforce and help us change the world through technology.
● Professional development opportunities with international customers.
● Collaborative work environment.
● Career path and mentorship programs that will lead to new levels.

Join Lean Tech and contribute to shaping the data landscape within a dynamic and 
growing organization. Your skills will be honed, and your contributions will be vital to our 
continued success. Lean Tech is an equal-opportunity employer. We celebrate diversity 
and are committed to creating an inclusive environment for all employees