The Role
Lead the design and delivery of a greenfield React Native iOS/Android app integrated with an existing platform. Define architecture, patterns, and tooling; consume GraphQL APIs; ensure performance, testing, CI/CD, and mentor engineers while collaborating with clients, designers, and backend teams.
Summary Generated by Built In
About Lab49
Lab49 is an NYC-based award‑winning specialist consultancy that creates bespoke technology in partnership with the world's leading financial institutions. Founded in 2002 to bring Silicon Valley engineering practices to Wall Street, we've delivered hundreds of high‑impact projects across global investment banks and buy‑side firms, spanning distributed systems, high‑performance automation, enterprise UX, cloud, and data‑driven platforms.
At Lab49, engineers work directly with clients to design and deliver production systems. We combine technology, design, and business to solve real problems where quality, performance, and clarity matter.
We are currently seeking a Senior React Native Engineer to design and build a new, greenfield mobile application for buy‑side investment management research workflows. The mobile app will integrate into an existing web‑based platform and will be built for iOS and Android from day one.
The Role
As a Senior React Native Engineer, you are an experienced, autonomous contributor who takes ownership of significant parts of a system and helps elevate the engineers around you.
This role sits at the intersection of hands‑on mobile engineering, architecture, and consulting. You will be the first mobile engineer on the initiative, responsible for defining the application foundations, establishing patterns, and making practical tooling decisions that enable long‑term success.
You will work directly with clients and collaborate closely with designers and backend engineers to ensure the mobile experience aligns cleanly with an existing platform, including shared design systems, domain models, and authentication.
This is a hybrid role, requiring 1 day per week at the office in central CDMX (Insurgentes Sur).
What You Will Be Doing
Technical Ownership & Delivery
- Start a new greenfield React Native application and drive it from early foundations through production release.
- Own the design and implementation of major features and core application architecture.
- Build high‑quality, scalable mobile experiences using React Native and modern JavaScript/TypeScript.
- Define and evolve patterns for navigation, state management, data access, error handling, performance, and testing.
- Integrate the mobile app into an existing platform by aligning with shared design systems, domain models, and authentication approaches.
- Consume a production GraphQL API implemented in .NET, collaborating with backend partners to evolve the schema as mobile requirements become clearer.
- Build data‑intensive views backed by paginated APIs, ensuring strong perceived performance and usability.
- Ensure testing, quality, and maintainability are built into the system from the start.
Leadership & Mentorship
- Work autonomously while guiding less‑experienced engineers through mentoring, pairing, and code reviews as the team grows.
- Lead small initiatives or workstreams and help ensure timely, high‑quality delivery.
- Act as a role model for strong engineering judgment, ownership, and collaboration.
Client & Stakeholder Collaboration
- Partner directly with client counterparts to understand user and business objectives.
- Collaborate closely with designers and partners on UX, wireframing, and high‑quality UI implementation.
- Communicate technical ideas clearly to both technical and non‑technical stakeholders.
- Contribute to building trust‑based client relationships as a reliable technical partner.
What Success Looks Like
- In your first 6–12 months, success means:
- You establish a strong mobile foundation and ship a production‑quality iOS and Android application.
- The mobile app integrates cleanly with the existing platform, aligning with shared design, domain, and authentication standards.
- You independently own and deliver key mobile components or features end‑to‑end.
- You proactively identify risks, trade‑offs, and improvement opportunities, addressing them early.
- Clients trust your judgment and value your contributions.
- Other engineers rely on you for guidance, clarity, and technical leadership as the mobile capability grows.
What You Should Have
- 6–8+ years of experience designing and building production software.
- Strong commercial experience building production mobile applications with React Native.
- Experience shipping and operating apps on both iOS and Android.
- Strong proficiency in modern JavaScript and TypeScript.
- Solid understanding of mobile application architecture, performance, and reliability.
- Experience consuming GraphQL APIs in production and collaborating on schema evolution.
- Solid understanding of SDLC practices, CI/CD, automated testing with tools such as Detox or Maestro, and code quality.
- Excellent written and spoken English communication skills (C1+ is highly preferred)
Bonus Points
- Experience defining architecture and patterns for greenfield products.
- Backend & cloud engineering exposure (.NET & Azure) to support cross‑team collaboration.
- Experience with cloud platforms and data‑intensive systems.
- Background in financial services, consulting, or similarly complex domains.
Why Lab49?
At Lab49, you'll work on complex, meaningful problems with talented engineers, designers, and consultants. You'll gain broad exposure to technologies, business domains, and client environments as you grow your career.
We value curiosity, judgment, and ownership. If you care about quality, enjoy helping others succeed, and want your work to have real impact, Lab49 is a place where you can thrive.
Our Hybrid Work Model
This role is based in Mexico City with a hybrid work model. Team members typically work in person one day per week, and more when needed, collaborating closely with teammates in Mexico and the US. We believe this balance supports both flexibility and the collaboration needed to deliver excellent outcomes.
Skills Required
- 6-8+ years of experience designing and building production software
- Strong commercial experience building production mobile applications with React Native
- Experience shipping and operating apps on both iOS and Android
- Strong proficiency in modern JavaScript and TypeScript
- Solid understanding of mobile application architecture, performance, and reliability
- Experience consuming GraphQL APIs in production and collaborating on schema evolution
- Solid understanding of SDLC practices, CI/CD, and automated testing (tools such as Detox or Maestro)
- Excellent written and spoken English communication skills (C1+ highly preferred)
Am I A Good Fit?
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The Company
What We Do
Serving Luxembourg's IT needs since 2002, ION Group has focused its activities on 3 pillars: ION Home: IT services for home users. - Computer repair and maintenance - Network Setup - Internet Setup - Email and Hosting Services ION Pro: Maintenance for small and medium businesses - Server maintenance and setup - Network configuration and security - Workstation - Server and services hosting and housing ION Development - Website design and development - Custom application development (Web, Mobile, iOS, Android) - OpenSource software modifications
