Senior Android Engineer - Kotlin, MVVM, Jetpack Compose

Hydrogen UK Ltd; City Of London; On-site; GBP 92,000 - 129,000; Full time

Job summary

Hydrogen UK Ltd is seeking an experienced Android Engineer for an initial 8-week engagement with potential extension. The role is hybrid and outside IR35, requiring Kotlin and modern Android experience in large production codebases.

You will work across Android, backend API interaction, and architecture reconnaissance to deliver robust mobile solutions. The position involves navigating large codebases, analyzing CI/CD pipelines, and collaborating with cross-functional teams under time pressure.

Qualifications

• Experience delivering Android apps with Kotlin and Jetpack Compose in large production codebases.
• Ability to read large codebases and map architectural layers.
• Fluent professional English, both written and spoken.
• Experience with REST/GraphQL/gRPC and API contracts.

Responsibilities

• Develop Android features using Kotlin and Jetpack Compose in hybrid/production environments.
• Navigate large codebases, perform static analysis and dependency mapping.
• Trace UI flows through networking to backend using REST/GraphQL/gRPC.
• Assess and integrate third-party SDKs and security considerations (OAuth/OpenID).
• Collaborate with engineers to drive architectural consistency and quality.

Skills

Kotlin

Jetpack Compose

MVVM

MVI

Clean architecture

Codebase navigation

CI/CD

OpenAPI

Tools

OpenAPI

GraphQL

gRPC

REST API

OAuth 2.0 / OIDC

Job description

Hydrogen UK Ltd is seeking an experienced Android Engineer for an initial 8-week engagement with potential extension. The role is hybrid and outside IR35, requiring Kotlin and modern Android experience in large production codebases.

You will work across Android, backend API interaction, and architecture reconnaissance to deliver robust mobile solutions. The position involves navigating large codebases, analyzing CI/CD pipelines, and collaborating with cross-functional teams under time pressure.