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 **** and were profitable in ****, 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 is 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
Join Tether and Shape the Future of Digital Finance
At Tether, we're not just building products, we're pioneering a global financial revolution.
Our cutting‐edge solutions empower businesses—from exchanges and wallets to payment processors and ATMs—to seamlessly integrate reserve‐backed tokens across blockchains.
By harnessing the power of blockchain technology, Tether enables you to store, send, and receive digital tokens instantly, securely, and globally, all at a fraction of the cost.
Transparency is the bedrock of everything we do, ensuring trust in every transaction.
Innovate with Tether
Tether Finance:
Our innovative product suite features the world's most trusted stablecoin, USDT, relied upon by hundreds of millions worldwide, alongside pioneering digital asset tokenization services.
Tether Power:
Driving sustainable growth, our energy solutions optimize excess power for Bitcoin mining using eco‐friendly practices in state‐of‐the‐art, geo‐diverse facilities.
Tether Data:
Fueling breakthroughs in AI and peer‐to‐peer technology, we reduce infrastructure costs and enhance global communications with cutting‐edge solutions like KEET, our flagship app that redefines secure and private data sharing.
Tether Education
Democratizing access to top‐tier digital learning, we empower individuals to thrive in the digital and gig economies, driving integral growth and opportunity.
Tether Evolution
At the intersection of technology and human potential, we are pushing the boundaries of what is possible, crafting a future where innovation and human capabilities merge in powerful, unprecedented ways.
Why Join Us?
Our team is a global talent powerhouse, working remotely from every corner of the world.
If you're passionate about making a mark in the fintech space, this is your opportunity to collaborate with some of the brightest minds, pushing boundaries and setting new standards.
We've grown fast, stayed lean, and secured our place as a leader in the industry.
If you have excellent English communication skills and is ready to contribute to the most innovative platform on the planet, Tether is the place for you.
About the job
Our pioneering P2P development platform, built on our open‐source technology stack, Pear, eliminates the need for traditional server infrastructure.
Pear platform facilitates direct deployment of applications from the developer's machine to the user, enabling seamless scalability and performance.
By leveraging Node.js‐based technology akin to BitTorrent, we create robust peer‐to‐peer connections and data replication systems that set the foundation for a decentralized web.
Keet, our flagship P2P communications app, is the first step towards this new era.
It exemplifies the potential of P2P technology in everyday applications, from messaging and file sharing to complex collaborative environments, all while maintaining user sovereignty over personal data.
Responsibilities
In this role,



you will be responsible for developing and maintaining Keet Desktop, our cross‐platform P2P communications application built with React and running on the Pear runtime.
You'll work on everything from UI/UX implementation to performance optimization, helping shape the future of decentralized communication.
Strong competency in state management (Redux, Redux Toolkit, Zustand, or similar).
Ability to write modular, maintainable, and well tested code.
Solid skillset in testing & debugging complex frontend applications.
Deep interest or experience with P2P technologies or distributed systems.
Comfort working in a remote, globally distributed team; good communication skills.
Preferred Qualifications
Experience with desktop application development (Electron, Tauri, or similar runtimes).
Familiarity with video/audio APIs (WebRTC, media streams) and real‐time communication.
Demonstrated ability to optimize UI performance: rendering, memory management.
Bonus: Past contributions to OSS projects, especially in P2P or decentralized tech.
About Darwoft
Darwoft is a software factory that builds custom software solutions and provides IT staff augmentation services for international clients, mainly in the United States and Latin America.
We partner with startups and fast‐growing companies to build high‐impact digital products.
Our culture is people‐first, focused on technical quality, long‐term relationships, and collaboration.
We combine technical excellence with a close, human approach to how we work.
Senior Frontend / UX Engineer – AI‐Driven Full Stack | Contractor | LATAM
General Information
Location: Remote – Latin America
Contract Type: Independent Contractor (full-time)
Industry / Project: Fintech – Digital Wallet for cross‐border payments
Time Zone: ART
English Level: B2
About the Role
We are looking for a Senior Frontend / UX Engineer to join a fast‐growing U.S. fintech company that is simplifying cross‐border payments and international money transfers, with a strong focus on the Latino community in the United States.
You will help build its Digital Wallet, the product through which users manage and move their money.
This is a frontend‐first role.
Your main job will be to build excellent user experiences: turning product requirements and UX/UI designs into intuitive, scalable, production‐ready wallet features.
You will also use AI‐powered development tools to extend your reach across the stack, including Backend for Frontend (BFF) services, API integrations, and supporting backend functionality, so you can deliver complete features on your own when needed.
We are looking for someone who goes beyond implementing screens.
You should understand how users interact with financial products, spot opportunities to improve the experience, and balance user experience, technical quality, and delivery speed.
Your work will directly affect how easily and confidently users send money to their families and manage their finances.
Responsibilities
Design, develop, and maintain high‐quality user interfaces for a Digital Wallet.
Translate UX/UI designs and product requirements into functional, intuitive, and responsive applications.
Collaborate with product and design teams to improve user journeys, interactions, and overall usability.
Own features end to end, from initial requirements through implementation and delivery.
Use AI‐powered development tools to speed up frontend and full‐stack development.
Build and maintain Backend for Frontend (BFF) services that support application requirements.
Implement API integrations and supporting backend functionality when needed.
Ensure consistency, performance, accessibility, and maintainability across the application.
Take part in code reviews and help improve development practices.
Find ways to simplify
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