Senior Mobile & Frontend Software Engineer - #2163707

Purpose of job:

Our aim is to become a market leader in the provision of Electric Vehicle charging solutions to Local Authorities and businesses, supporting the transition to a zero-carbon future.

The goal is to undertake an ambitious electric vehicle charging installation program, deploying high volume and quality EV installations across the nation. Our aim is to make the world a better place, one charge point at a time.

The Senior Mobile and Front End Software Engineer will work within Zest’s IT team, primarily focused on the development of our mobile App, but also working with other developers in the creation of the applications to support our EV charge points management platforms.

Key Accountabilities:

The role is responsible for the following:

Core React & React Native Skills:

• Strong commercial experience with React and React Native
• Proficiency in JavaScript (ES6+), TypeScript and nodeJS
• Experience with Expo
• Solid understanding of functional components
• React Hooks (useState, useEffect, useMemo, useCallback)
• Component lifecycle in React Native
• Experience building cross‑platform mobile applications from a single codebase
• Familiarity with React Native architecture (JS thread, UI thread, bridge, TurboModules)
• Offline‑first implementation (SQLite)

State Management & Data Handling:

• Experience with state management solutions:
• Zustand
• Context API
• Experience with React Query / TanStack Query for async data fetching, caching, and retries
• Integration with REST APIs
• Secure handling of authentication tokens and sensitive data

Mobile UI & Navigation:

• Building responsive, adaptive UIs for different screen sizes
• Experience with mobile navigation libraries:
• Expo Router
• React Navigation (stack, tab, drawer)
• Styling approaches:
• StyleSheet API
• Maps integration (react-native-maps, clustering, geolocation)
• Awareness of platform‑specific UI/UX differences between Android and iOS
• Accessibility best practices (screen readers, hit targets, contrast)

Platform‑Specific Experience (Android & iOS):

• Understanding of Android and iOS application lifecycles
• Handling runtime permissions, background tasks, and push notifications (FCM, APNs)
• Familiarity with Android Studio, Xcode, emulators/simulators, and physical devices
• Gradle builds and configuration (Android)
• Code signing, certificates, and provisioning profiles (iOS)
• Apple Human Interface Guidelines awareness
• Debugging using platform tooling (Logcat, Xcode tools)

Native Integration:

• Using and configuring native modules
• Ability to integrate third‑party native SDKs

Mobile Security:

• SSL pinning implementation
• Jailbroken/rooted device detection
• Secure token handling and encrypted storage

Performance & Optimisation:

• Performance profiling and optimisation in React Native
• Reducing unnecessary re‑renders and memory usage
• Optimising lists (FlatList, SectionList)
• Managing animations and gestures efficiently
• Analytics, crash reporting, and monitoring (Firebase, GA)

Testing & Quality:

• Unit testing with Jest
• Use of linting and formatting tools (ESLint, Prettier)

Build, Release & Tooling:

• Git‑based version control workflows
• CI/CD for React Native apps (via ADO)
• Experience delivering apps to Google Play Store and Apple App Store, with knowledge of store guidelines, review processes, and release management
• Familiarity with environment configuration (dev, staging, production)

Other:

• Ensure efficient coding standards are defined and applied to all developments
• Developing improvements in development tools to support project work
• Mentor IT developers in code development
• Any other duties as required

Outcome, Results and Key Performance Indicators:

• Documented solutions for all deliverables
• Provision of secure re-usable automation code
• Re-creatable (automated build and test) for all deliverables
• Successfully meeting the goals of the IT team

Key Relationships:

• Internal – All Developers, Product Owner, QA Engineer, Platform Engineer, Solution Architect, Project Managers, CTO

Knowledge and Skills:

• At least 5 years development experience in mobile applications
• Development using TypeScript, React, React Native
• Experience consuming and integrating REST APIs
• Firebase experience desirable (Analytics, App Check, Crashlytics, Performance Monitoring)
• Understanding of AWS best practices and architectures
• API build, scaling, and security within serverless and containerised AWS environments
• OCPP & OCPI protocols desirable
• Commitment to rigorous processes
• Knowledge of Firebase

Behaviours:

• Self-motivated self-starter
• Driven and able to work to tight deadlines
• Flexible and creative
• Patient and personable
• Excellent communication skills, able to articulate ideas and solutions at all levels of the business
• Approachable and supportive mentor
• Good attention to detail
• Analytical problem-solving

Qualifications:

• Educated to degree level or equivalent is preferred

Zest is an equal opportunity employer, committed to the values and ultimately societal benefits of diversity, equity, and inclusion.

We welcome applications from all backgrounds and are proud to support the Armed Forces Covenant, Disability Confident scheme, and Care Leaver Covenant as part of our commitment to an inclusive and supportive workplace.