Senior Mobile Engineer (React Native)

Transreport; Greater London; On-site; GBP 90,000 - 120,000; Full time

Benefits offered by this job

25 days holiday

Free flu jab for you and your family

Job summary

Transreport is hiring a Senior Mobile Engineer to own a greenfield React Native product for iOS and Android, collaborating with our Ruby on Rails engineers. This high-autonomy role will define architecture, testing, CI/CD, and release foundations while aligning with Product and Design.

You will lead the mobile roadmap, deliver a scalable cross-platform foundation, and drive measurable improvements in quality, stability, and delivery velocity.

Qualifications

• 6+ years of mobile engineering experience.
• Deep React Native and TypeScript expertise across architecture, testing, performance, and production delivery.
• Strong judgement about when React Native needs native platform capabilities or modules.
• Proven experience designing a greenfield system and shipping production iOS and Android applications.
• Experience establishing a development environment and technical direction from scratch.
• Comfortable explaining trade-offs between delivery speed, product needs, and maintainability.
• Ability to manage ambiguity, own multiple verticals, and move between architecture and hands-on delivery.
• Strong communication skills, surfacing delivery confidence, risks, dependencies, and technical debt.
• Experience collaborating with Ruby on Rails or similar backend teams.
• Experience in transport, logistics, or regulated industries.
• Familiarity with mobile observability, performance profiling, testing, and app-store releases.
• Experience working in B2B SaaS environments.
• Exposure to native iOS and Android development.

Responsibilities

• Architect & Build - Define, own, and ship a greenfield React Native B2B application for iOS and Android. Set architectural standards for near-term delivery and long-term scalability.
• Own Delivery - Manage multiple workstreams in a small team, turning product goals into technical plans and carrying them through build, release, and iteration.
• Design for the Long Term - Make pragmatic greenfield architecture decisions balancing delivery speed with maintainability, scalability, accessibility, and technical debt.
• Partner with Backend - Work with Rails engineers to shape API contracts, data flows, authentication, observability, and a sustainable mobile/backend boundary.
• Technical Leadership - Proactively communicate timelines, delivery confidence, dependencies, risks, and trade-offs to help product and engineering decisions.

Skills

React Native

TypeScript

Architecture

Performance

Testing

CI/CD

Backend integration

Communication

Regulated industries

B2B SaaS

Mobile observability

App store releases

Native iOS/Android

Job description

Accessible rail travel depends on systems that work reliably in live environments.

Our Passenger Assistance platform turns passengerassistancerequests into coordinated action inside live rail operations.

We’rehiring a Senior Mobile Engineer to architect, own and ship a greenfield React Native product for iOS and Android alongside our Ruby on Rails engineers.

Strategic Context

Transreportexists to remove structural barriers in rail travel. Our vision is that everyone has access to travel everywhere.

Weoperateacross the UK, Japan, and the EU and have supported over 10 millionassistancerequests for more than 1.8 million users.We are a Series A company recognised with a King’s Award.

As we scale internationally, this role will lead a new React Native application andestablisha scalable development environment across iOS, Android, and our backend platform.

Outcomes & Impact

Within 6months, you will

• Architect and launch the first production version of our new B2B React Native application.
• Establish the greenfield architecture, testing, CI/CD, and release foundations for iOS and Android.
• Agree scalable API contracts and an integration strategy with our Ruby on Rails engineers.
• Build trust across Product, Design, and Engineering by surfacing timelines, risks, trade-offs, and technical debt early.

Within 12 months, you will

• Own the mobile roadmap across multiple product verticals, from technical design to production.
• Build a maintainable cross-platform foundation for fast, sustainable delivery.
• Introduce measurable improvements in mobile quality, stability, performance, and delivery velocity.
• Shape long-term mobile/backend integration and keep technical debt visible and manageable.

Responsibilities

• Architect & Build - Define, own, and ship a greenfield React Native B2B application for iOS and Android. Set architectural standards that balance near-term delivery with long-term scalability.
• Own Delivery - Own multiple workstreams in a small team, turning product goals into technical plans and carrying them through build, release, and iteration.
• Design for the Long Term - Make pragmatic greenfield architecture decisions, balancing delivery speed with maintainability, scalability, accessibility, and technical debt.
• Partner with Backend - Work with Ruby on Rails engineers to shape API contracts, data flows, authentication, observability, and a sustainable mobile/backend boundary.
• Technical Leadership - Proactively communicate timelines, delivery confidence, dependencies, risks, and trade-offs, helping Product and Engineering make informed scope decisions.

This high-autonomy role suits an engineer comfortable defining what to build, designing the system, and delivering it—not simply implementing prescribed solutions.

The Tech Environment:

Target Stack

• React Native (TypeScript)
• React Navigation

Backend & Delivery Context

• Ruby on Rails APIs
• iOS and Android app delivery
• API contracts and mobile/backend integration
• Automated testing and CI/CD
• Mobile monitoring and performance optimisation
• App Store and Google Play release practices
• Security, accessibility, and maintainable engineering standards

You are not expected to know every toolimmediately, but you must be comfortable owning architectural decisions across React Native and its backend integration.

Requirements

MustHaves

• 6+ years of mobile engineering experience.
• Deep React Native and TypeScriptexpertiseacross architecture, testing, performance, and production delivery.
• Strong judgement about when React Native needs native platform capabilities or modules.
• Proven experience designing a greenfield system and shipping production iOS and Android applications.
• Experienceestablishinga development environment and technical direction from scratch.
• Comfortable explaining trade-offs between delivery speed, product needs, and maintainability.
• Ability to manage ambiguity, own multiple verticals, and move between architecture and hands-on delivery.
• Strong communicationskills, proactively surfacing delivery confidence, risks, dependencies, and technical debt.
• Experience collaborating with Ruby on Rails or similar backend teams.
• Experience in transport,logistics, or regulated industries.
• Familiarity with mobile observability, performance profiling, testing, and app-store releases.
• Experience working in B2B SaaS environments.
• Exposure to native iOS and Android development.
• 25 days holiday
• Freeflu jab for you and your family

We value

• Clarity over bureaucracy

Weoperatewith high autonomy and high accountability. People are expected to raise risks early, communicate clearly, and take responsibility for outcomes.

Interview Roadmap

• ScreeningCall (30 mins)
• Technical Architecture Discussion –Greenfield React Native and backend integration deep dive
• Final Culture Conversation– Leadership alignment

We’rea Disability Confident employer and we welcome applications from disabled candidates. If you need any adjustments at any stage of the recruitment process, please tell us what would help -we’llwork with you to make the process as accessible as possible.

We also offer a Guaranteed Interview Scheme (GIS) for candidates who consider themselves to have a disability as defined under the Equality Act 2010.

If youindicatethisoptionin your application and your applicationdemonstratesthat you meet the essential criteria for the role,you’llbe invited to interview or assessment.

Choosing GISdoesn’tguarantee a job offer. If you have any questions, please get in touch.