React/Node Mobile Field Tool Developer — iOS Safari & Android Chrome

I am hiring a developer to take over an existing specialized mobile web application already in development. This is not a greenfield project. There is an existing codebase, an active product, documented QA, field-review directives, and a defined remediation backlog. The next developer will pick up from the current state and execute against clear implementation priorities. The product is a mobile/browser-based field tool used by professionals in a fast-moving, real-world environment. It must perform reliably on tablet and phone, especially on iOS Safari and Android Chrome. Ease of use is the single most important requirement. The tool is used under pressure in the field — every interaction must be fast, obvious, and require as few taps as possible. A quick-access dashboard is critical. Workflows must be streamlined so that users can complete tasks with minimal friction and zero confusion. Current stack React SPA frontend Node.js / Express backend MongoDB Mobile web / PWA workflow SVG-based interactive annotation interface What the next developer will be working on The work starts from the current implementation and existing QA / sprint directives, including items such as: Queue and session flow fixes Auto-advance / next-item behavior Touch workflow and mobile UX improvements — fewer taps, faster flows Quick-access dashboard improvements SVG annotation logic Structured data capture improvements Export and record integrity improvements Bilingual UI labeling Determination workflow fixes Handwriting / freehand annotation layer as a later scoped item Ongoing field-driven remediation and refinement What I need A developer who can read an existing codebase quickly and take ownership Strong instinct for mobile UX — minimal taps, logical flow, fast feedback Ability to simplify and streamline UI without breaking existing functionality Strong React / frontend debugging ability Comfort working across frontend + backend when needed Strong mobile browser experience on iOS Safari and Android Chrome Experience with touch interactions, SVG/canvas interaction, and field-tool UX Preferably experience with handwriting or stylus input in browser-based tools Important This is a real continuation role. I am not looking for someone who only wants to build from scratch and ignore the current implementation. You should be comfortable inheriting existing architecture, understanding current constraints, and shipping improvements in priority order. You will be taking over from the current development state, not starting from zero. Before I share access/details, answer these questions in your proposal 1. What mobile touch issues have you personally encountered on iOS Safari and Android Chrome, and how did you fix them? 2. Do you test on physical devices, not only simulators? Which ones? 3. Will you personally do this work, or will any part be handed to someone else? 4. What experience do you have taking over an existing React / Node codebase and improving it without starting over? 5. What experience do you have with SVG, canvas, annotation tools, or handwriting/stylus input in a mobile web app? Proposal requirements Individual freelancers only — no agencies Fixed price only Include your price for the first milestone / first sprint Include your timeline Include examples of relevant mobile web work Proposals that do not answer the questions above will not be considered.