Mobile App Developer - London
Job Title: Mobile App Developer
Location: Stratford, London (4 x per week working on site)
Salary/Rate: Up to £537 per day
Start Date: Feb 2026
Job Type: 11 month (Inside IR35 contract)
Role overview:
We are currently recruiting for an experienced Mobile App Developer to join our global client in the automobile manufacturing industry. Immediate interview & start available via Square One Resources.
Responsibilities:
Technical Leadership: Translate business needs into technical solutions, ensuring they conform to architectural standards. Own the technical backlog, manage technical debt, and ensure code is structured to meet emerging requirements.
Delivery & Operations: Ensure CI/CD pipelines are maintained, releases are shipped consistently, and blockers are resolved.
Mentorship: Support the growth of fellow engineers, acting as a mentor to 6 software engineers across the team.
Collaboration: Proactively work with external Back End teams (including Pro Telematics, Charging, and Transportation Mobility Cloud). Work with the Front End team to ensure UX alignment with platform conventions.
Community: Be an active part of the development community, sharing best practices, identifying cross-product alignment opportunities, and defining coding standards.
Technical Experience Required:
Java Ecosystem: Extensive software development experience in JVM languages (Java, Kotlin) across multiple projects, with deep knowledge of Spring and Spring Boot Frameworks.
Cloud & Infrastructure: Experience with Google Cloud Platform (GCP) products (eg, Cloud Run, PubSub, Secret Manager).
Observability: Experience implementing and utilising observability and monitoring tools (eg, Grafana, Splunk) to maintain system health and diagnose issues.
API Design: Experience designing and developing REST APIs and associated QA tools.
Technical Experience Preferred
Engineering Practices: Passion for Software Craftsmanship with experience in Pair Programming, Mobbing, and Test-Driven Development (TDD).
Delivery: Proven track record of delivery, tackling complex engineering problems, and operating with autonomy.
Communication: Strong written and verbal communication skills, capable of mentoring others and presenting to technical and non-technical stakeholders.
Adaptability: Ability to quickly learn and apply architectural and security standards.
Tools: Experience with version control systems (eg, Git).
Other experience Required:
DevOps experience (CI/CD pipeline management).
Experience with Load/Performance testing and scaling applications.
Previous experience integrating with mobile applications.
Work Experience: Evidence of having successfully fulfilled Senior Engineer positions
Collaborative: A passion for building inclusive team cultures.
Proactive: Ability to flourish independently and navigate ambiguity ("work in shades of grey").
Flexible: Capable of multitasking and handling complex projects.
Supportive: Prepared to spend time supporting and mentoring junior team members.
If you are interested in this opportunity, please apply now with your updated CV in Microsoft Word/PDF format.
Disclaimer
Notwithstanding any guidelines given to level of experience sought, we will consider candidates from outside this range if they can demonstrate the necessary competencies.
Square One is acting as both an employment agency and an employment business, and is an equal opportunities recruitment business. Square One embraces diversity and will treat everyone equally. Please see our website for our full diversity statement.