Senior React + React Native Developer

KLEES; United States; Remote; USD 120,000 - 180,000; Full time

Job summary

KLEES is seeking a frontend engineer to build features across a web administration experience and a mobile app used by field teams. You’ll work with product and design, contribute to regular releases, and improve usability, accessibility, and performance on both platforms.

You’ll develop TypeScript features for React web apps and React Native mobile apps, create reusable accessible components, and support English, Spanish, and Portuguese localization while advancing offline-first workflows and

Qualifications

• At least 5 years building production React applications.
• At least 2 years with React Native, or equivalent depth in native iOS or Android development.
• Strong TypeScript skills and experience with modern testing practices.
• Familiarity with REST APIs, JWT authentication, and real‑time WebSocket flows.
• Care for the experience of non‑technical users.

Responsibilities

• Develop TypeScript features for React web applications and React Native mobile apps.
• Create reusable, accessible components and support English, Spanish, and Portuguese localization.
• Improve offline-first mobile workflows, including queued sync and conflict handling.
• Review code, mentor junior engineers, and take part in an on‑call rotation of one week in six.
• Maintain performance targets, including a mobile JavaScript bundle below 4 MB and web LCP below 2.5 seconds.

Skills

React

React Native

TypeScript

Testing

Job description

Role overview

Build product features across a web administration experience and a mobile app used by field teams. You’ll work closely with product and design, contributing to regular releases while improving usability, accessibility, and performance across both platforms.

Responsibilities

• Develop TypeScript features for React web applications and React Native mobile apps.
• Create reusable, accessible components and support English, Spanish, and Portuguese localization.
• Improve offline-first mobile workflows, including queued sync and conflict handling.
• Review code, mentor junior engineers, and take part in an on‑call rotation of one week in six.
• Maintain performance targets, including a mobile JavaScript bundle below 4 MB and web LCP below 2.5 seconds.

Requirements

• At least 5 years building production React applications.
• At least 2 years with React Native, or equivalent depth in native iOS or Android development.
• Strong TypeScript skills and experience with modern testing practices.
• Familiarity with REST APIs, JWT authentication, and real‑time WebSocket flows.
• Care for the experience of non‑technical users.

Nice to have

• Experience with Expo EAS for builds or over‑the‑air updates.
• Mapping or geolocation work, such as MapLibre or Mapbox.
• English and Spanish fluency.