Mobile Architect - Outside IR35

Hydrogen Group ·www.hydrogengroup.com

Location City of London, London, England
Work type Hybrid
Salary GBP 800 - 900 / month
Type Full time
Level Mid
Source Shazamme
Technology
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My client is looking for an experienced mobile architect to join their team on an initial 8 week piece of work with a good possibility to extend. This is a hybrid role and is outside of IR35.

Able to reconstruct architecture of large existing systems from code, interviews and incomplete artefacts - demonstrable, with examples; Fluency in structured modelling approach (C4, arc42, UML, ADRs). Documentation-as-code tooling, diagramming tools, Confluence/Miro.

Defining architecture characteristics and quality attributes, and assessing a system against them.

Platform bias: iOS depth expected. Must be conversant enough in Android to challenge and review docs and assessment findings.

iOS (primary depth)

  • Swift, UIKit and SwiftUI in large production apps; understands the realities of a mixed UIKit/SwiftUI estate
  • Modularisation at scale: SPM, Xcode workspaces, Tuist/XcodeGen, XCFrameworks, module boundary and dependency management
  • Hands-on experience of architectural patterns in large production apps (MVVM, VIPER, TCA, Clean-style layering), and the ability to identify which one a codebase follows;
  • Build, signing and distribution mechanics; profiling and performance analysis

Android (working knowledge)

  • Kotlin, Jetpack Compose, Gradle multi-module builds: enough to read, question and validate, not necessarily to write

Backend, API and integration

  • Mobile-to-backend integration patterns: BFF, API gateway, REST/GraphQL/gRPC, versioning and contract management
  • Identity and authorisation: OAuth 2.0, OIDC, token lifecycle, session management, step-up authentication; FAPI and Open Banking awareness
  • Understanding of how a bank's mobile app sits on top of core banking, payments and legacy estates, including mainframe-fronted services

Essential non-technical skills

  • Executive stakeholder management: can hold a room with CTO-level stakeholders, present findings without softening them or turning them into an accusation
  • Elicitation under resistance - gets useful answers from people who suspect they are being assessed
  • Written clarity for mixed audiences
  • Scope discipline: recognizes rabbit holes early and closes them protecting a fixed-price approach
  • Independent judgement: willing to state a conclusion on partial evidence, and to label clearly where confidence is low
  • Pace: comfortable producing a defensible first cut in week two for discussion and refining, rather than perfecting until week seven
  • Fluent professional English, spoken and written

Nice to have

  • Prior delivery inside a UK or EU retail bank, or comparably regulated environment
  • Experience of a mobile platform modernisation or re-platforming programme, in either direction
  • Cross-platform estates: Kotlin Multiplatform, React Native, hybrid/webview components
  • Consultancy background; experience scoping and defending fixed-price work

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Frequently asked questions

Who is hiring for the Mobile Architect - Outside IR35 role?
Hydrogen Group is hiring for the Mobile Architect - Outside IR35 position, a Shazamme client. Apply directly on the employer's career site.
Where is the Mobile Architect - Outside IR35 job located?
The Mobile Architect - Outside IR35 role with Hydrogen Group is based in City of London, GB. The role is hybrid-friendly.
Is the Mobile Architect - Outside IR35 role remote?
Yes — the Mobile Architect - Outside IR35 position at Hydrogen Group is hybrid. Candidates based in GB are preferred.
What does the Mobile Architect - Outside IR35 role pay?
Hydrogen Group lists the Mobile Architect - Outside IR35 role at GBP 800–900 per month.
Is the Mobile Architect - Outside IR35 role full-time or contract?
This is a full time position at Hydrogen Group.
What experience level is the Mobile Architect - Outside IR35 role?
The Mobile Architect - Outside IR35 position is aimed at mid-level candidates.
How do I apply for the Mobile Architect - Outside IR35 role at Hydrogen Group?
Apply directly on Hydrogen Group's career page via the Apply button on this listing. ZammeJobs links straight through to the employer's ATS — no third-party form, no resume database.
Apply direct