Xamarin Dev – Id #00011

Werben HR LLC; Tandil; Remote; ARS 86,234,000 - 120,727,000; Full time

Job summary

Werben HR LLC seeks a mobile developer to own a new offline-first iOS/Android app from project setup through public launches on App Store and Google Play. You’ll work in two-week sprints with AI coding tools daily and operate with a single app across both stores.

You’ll review diffs, write tests, and decide on sync/storage and release strategies, reporting to leadership alongside the lead and backend developers. This role is fully remote from LATAM with ~40 hours/week.

Qualifications

• 4+ years building mobile apps, including React Native releases to iOS and Android.
• Offline-first architecture with local storage, queued writes and retries.
• Performance tuning for low-end Android devices with measurable impact.
• Daily use of AI coding tools (Cursor/Claude Code) in production with TypeScript and CI.
• Clear written and spoken English for client communications and PR notes.

Responsibilities

• Set up Apple and Google developer accounts, signing, CI builds and testing tracks.
• Build local storage, write queue and retry logic for offline use.
• Define sync and upload APIs with backend developer; resolve conflicts.
• Implement phone-number sign-in with SMS codes and push notifications fallback.
• Handle store submissions, privacy disclosures, and monitoring artifacts.

Skills

Mobile development

Offline-first architecture

Performance optimization

AI coding tools

English communication

CI/CD

Tools

Cursor

Claude Code

Job description

Our client is a remote product studio that builds MVPs and custom software for startups and companies past the idea stage. Clients pay for each build, and a small team works in two-week sprints with AI coding tools used every day. Clients are startup founders and their teams, so developers explain tradeoffs to them directly.

They've been at it since 2020 and were profitable in 2025, with a 30% net margin. After building their own AI systems, they tripled monthly revenue with the same team size. Clients rate them 4.9 out of 5 in verified reviews, and the startups they build for have raised more than $25M in venture funding.

Your Role

You'll be the only mobile developer on a new offline-first iOS and Android app, starting from the first project setup. The developer accounts, build pipeline and release tracks don't exist yet, so that's where you begin, and you stay on the same app through its public launch on the App Store and Google Play.

Sprints run two weeks with four to five features each, and coding agents write most of the first draft. You review every diff, add the tests the agents missed, and make the calls on sync, storage and releases. If you'd rather have a QA team or a release manager handle testing and store submissions, this probably isn't the right seat.

You report to the studio's leadership and work day to day with the lead developer and a backend developer, who's your counterpart on the sync and upload APIs. You'll also write risk notes and tradeoffs directly to the client team, with your recommendation attached. Success means sprints that close with their acceptance criteria verified, a write queue that neither loses nor doubles a submission on real devices, and an app live on both stores where sync failures show up in monitoring before anyone reports them.

You’ll

• Set up Apple and Google developer accounts, signing, CI builds and testing tracks
• Build the local storage, write queue and retry logic that keep the app working offline
• Agree the sync and upload APIs with the backend developer, and decide how conflicting edits resolve
• Build phone-number sign-in with SMS codes, and push notifications that fall back to SMS
• Build camera capture and e-signature flows that save each signed record as a new version
• Measure and improve startup time, memory and app size on low-end Android phones
• Handle store submissions, privacy disclosures and review rejections, and add crash and sync monitoring

You Bring

• 4+ years building mobile applications, including React Native applications released on both the App Store and Google Play
• Offline-first work you built yourself: local storage, queued writes, retries and conflict handling
• Performance tuning on low-end Android, with startup time or memory measured before and after a change
• Daily use of Cursor, Claude Code or a similar AI coding tool on production mobile work, with TypeScript, automated tests and CI around it
• Clear written and spoken English for PR descriptions, risk notes and tradeoff explanations to a client team
• Experience working from written acceptance criteria, and the judgment to push back on a merge that misses them

Bonus Points

• An in-app e-signature or document flow that stored versioned records
• An application built for field, frontline or hourly workers
• A localized application, or Spanish for testing the interface
• Backend work such as writing an endpoint or a database migration
• Crash reporting or sync monitoring you set up and then used to fix a problem seen in the field

What's Offered

• Fully remote contractor role from LATAM, full time at about 40 hours a week
• Core hours in US time zones, overlapping with the lead developer and the backend developer
• One app to own, from the first project files through public release on both stores
• Sync, storage and release decisions that are yours to make, with a backend developer as your counterpart
• A team where AI coding agents are part of the daily workflow, with typed code, automated tests and CI in place

Interview Process

• Intro Call: 30 minutes with atomic HR on your background and goals
• Leadership Screening: A short call, possibly with an async part first
• Product and Developer Conversation: How you take features to merge and agree sync APIs
• Take-Home Test: One feature like the real scope, built and checked