Xamarin Dev – Id #00011

Werben HR LLC; Municipio de Rincón de los Sauces; Remote; ARS 85,158,000 - 149,026,000; Full time

Benefits offered by this job

Fully remote LATAM contractor

40 hours per week

Core hours US time zones

Job summary

Werben HR LLC client seeks a mobile developer for an offline-first iOS/Android app. Start from the first project setup and own the app through public launches on the App Store and Google Play.

You will review every diff, add tests the agents missed, and decide on sync, storage and release strategies. The role emphasizes direct client communication and delivering a robust, low-latency mobile experience.

This is a fully remote LATAM contract with US-aligned core hours and four two-week sprints.

Qualifications

• 4+ years building mobile applications and React Native releases on App Store and Google Play.
• Offline-first experience with local storage, queued writes and retry logic.
• English communication for client-facing risk notes and tradeoffs.

Responsibilities

• Set up app 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 dev and resolve conflicts.
• Implement sign-in, push notifications, and versioned records.
• Tune performance on low-end Android devices and manage store submissions.

Skills

Mobile development

React Native

English communication

TypeScript

Code reviews

Tools

Cursor

Claude Code

CI/CD tooling

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