UI Engineer

Valarian Technologies Limited
London, United Kingdom
HybridCareer-pivot friendly

Who this role is best for

Strong fit for UI engineers who bridge web and native mobile environments and advocate for secure, accessible user experiences.

Best fit for

  • Candidates with experience in both React/TypeScript and native mobile development (Swift or Kotlin/Java)
    — “working primarily with React/TypeScript for complex web dashboards and administrative consoles, alongside native mobile platforms using Swift (iOS) or Kotlin/Java (Android)”
  • Candidates who prioritize security in UI design and understand zero-trust environments
    — “This role requires someone who can build fluid, intuitive interfaces while reasoning clearly about client-side trust boundaries, data leakage prevention, authentication flows, and operational security.”

Things to consider

  • Requires ownership of complex systems and technical ambiguity, not just ticket resolution
    — “This is not a role for someone who only wants to take tickets.”
  • Candidates must be willing to work on mission-critical systems with high security demands
    — “protecting sensitive government and commercial workflows”

How to stand out

  • Highlight experience with secure token handling and zero-trust session management in your resume
    — “Address client-side security concerns: secure token handling, biometric authentication, encrypted local cache, certificate pinning, and zero-trust session management.”
  • Showcase your ability to optimize UI performance under varying network and device conditions
    — “Diagnose and optimize UI performance bottlenecks across browsers and mobile hardware.”
  • Emphasize your track record in building scalable design systems for cross-platform use
    — “Build and maintain a scalable design system that ensures aesthetic consistency, compliance, and strict usability across both desktop and mobile form factors.”
  • Demonstrate your ability to collaborate with UX designers and security specialists on critical workflows
    — “Partner closely with product managers, UX designers, backend engineers, and security specialists to turn mission-critical requirements into clear interfaces.”
  • Include examples of end-to-end feature ownership and deployment in your interview narrative
    — “Strong track record of end-to-end feature ownership from Figma mocks to app deployment and post-release monitoring.”
Pace · Fast PacedCollaboration · HighAutonomy · MediumDecision Impact · Team

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

  • high-performance, accessible, and secure user interfaces
  • own client applications from technical design and UI component implementation through to testing, deployment, observability, and production operations
  • integrate complex RESTful and WebSocket/event-driven APIs
Typical background
UI/UX designfront-end development

Skills & requirements

Required

Design, Build, And Maintain Mission-critical User InterfacesWork With React/typescript For Complex Web Dashboards And Administrative ConsolesNative Mobile Platforms Using Swift (ios) Or Kotlin/java (android)Client-side PerformanceLocal EncryptionAccessible Design SystemsCross-platform Reliability

Preferred

Modular Component ArchitecturesCi/cd Testing PipelinesWeb And Mobile PackagingOffline-first Sync StrategiesSecure Local Storage

Stack & domain

ReactTypeScriptSwiftKotlinJavaRestful ApisWebsocketCi/cd Testing PipelinesOffline-first Sync StrategiesSecure Local StorageUser SafetyAccessibilityChallenging AssumptionsTranslating Ambiguous Workflows Into Crisp, Resilient User ExperiencesSecurityMilitaryCommercial

About the role

Original posting from Valarian Technologies Limited via Lever

Valarian Technologies is a dual-use technology company building critical tools to safeguard the future in an era of evolving global security challenges. We're rethinking security beyond traditional military domains, addressing asymmetric threats that impact our technological advantage, economic strength, and democratic institutions.

We build Acra – the platform foundation for everything we do as a dual-use technology company. The platform’s name, rooted in the Greek word for citadel (or, fortress), reflects the design and purpose of our infrastructure-agnostic secure enclaves: protecting critical data. Some of the government and commercial workflows include: increased operational resiliency for mission-critical systems and functions; enabling organisations to more quickly and widely adopt emerging technologies while ensuring the integrity of their intellectual property; information flow during disaster response scenarios, and zero-trust / least-privilege environments for M&A, attorney-client privileged communications, etc. And we’ve only scratched the surface.

At our core, we're driven by a shared mission and a belief in making a tangible impact on our world. Whether you join our London HQ or the wider global organisation, you’ll be a part of collaborative, high-performing teams, creating cutting-edge software, platforms, and infrastructure.

The Role

You will design, build, and maintain mission-critical user interfaces for Acra, our secure-enclave platform protecting sensitive government and commercial workflows.

You will bridge web and native mobile environments—working primarily with React/TypeScript for complex web dashboards and administrative consoles, alongside native mobile platforms using Swift (iOS) or Kotlin/Java (Android) to deliver responsive, zero-trust client applications for operators in the field. You will own front-end systems end-to-end: from UI architecture, state management, and API integration down to client-side performance, local encryption, accessible design systems, and cross-platform reliability.

You will help shape the frontend delivery foundations, including modular component architectures, CI/CD testing pipelines, web and mobile packaging, offline-first sync strategies, and secure local storage.

ACRA’s architecture separates the control plane, platform enforcement layer, and isolated execution environments. This role requires someone who can build fluid, intuitive interfaces while reasoning clearly about client-side trust boundaries, data leakage prevention, authentication flows, and operational security.

This is not a role for someone who only wants to take tickets. We are looking for someone who understands the product vision, advocates for user safety and accessibility, challenges assumptions, and translates ambiguous workflows into crisp, resilient user experiences.

What you’ll do:

Architect and build high-performance, accessible, and secure user interfaces across React/TypeScript and native mobile clients (Swift/iOS or Android).

Own client applications from technical design and UI component implementation through to testing, deployment, observability, and production operations.

Integrate complex RESTful and WebSocket/event-driven APIs, handling real-time data streaming, optimistic updates, and offline/low-bandwidth resilience.

Build and maintain a scalable design system that ensures aesthetic consistency, compliance, and strict usability across both desktop and mobile form factors.

Address client-side security concerns: secure token handling, biometric authentication, encrypted local cache, certificate pinning, and zero-trust session management.

Partner closely with product managers, UX designers, backend engineers, and security specialists to turn mission-critical requirements into clear interfaces.

Diagnose and optimize UI performance bottlenecks across browsers and mobile hardware (frame rates, bundle size, memory footprint, battery impact).

Establish frontend and mobile testing best practices (unit, component, and end-to-end integration tests).

Raise engineering standards through design reviews, accessible code practices, and thorough documentation.

Operate independently in a fast-paced environment with strong ownership and product thinking.

What we are looking for:

Strong professional engineering experience building production-grade web applications with modern React and TypeScript.

Solid hands-on native mobile development experience with Swift (iOS) or Kotlin/Android (or proven experience bridging cross-platform architectures with native modules).

Deep understanding of modern UI architecture, state management paradigms, and responsive design systems.

Experience consuming, designing, and optimizing APIs (REST, WebSockets, or GraphQL) for client performance and intermittent connectivity.

Familiarity with client-side security fundamentals (content security policies, token management, secure device storage, threat modeling at the client layer).

Strong track record of end-to-end feature ownership from Figma mocks to app deployment and post-release monitoring.

Disciplined approach to automated testing (Jest, React Testing Library, XCTest/Espresso, Playwright/Cypress).

Excellent debugging skills across web browsers, native mobile runtimes, device profiles, and network conditions.

Product-minded engineering judgment: you care deeply about how users navigate critical workflows, not just what ticket needs to be resolved.

A self-driven, ownership-oriented mindset comfortable with technical ambiguity and fast feedback loops.

Nice to have:

Experience building interfaces for secure or regulated environments (defence, government, cybersecurity, fintech, or critical infrastructure).

Familiarity with WebAssembly (Wasm), client-side cryptography, or zero-knowledge protocols.

Hands-on experience with native mobile app deployment, MDM (Mobile Device Management) enterprise distribution, or App Store / Play Store governance.

Experience with real-time collaborative interfaces, mapping/GIS visualisations, or tactical telemetry dashboards.

Familiarity with container-based frontend workflows, mobile CI/CD pipelines (Fastlane, GitHub Actions), and frontend observability tools (Sentry, Datadog RUM).

Systems where auditability, accessibility compliance (WCAG 2.1+), and operational evidence are first-class requirements.

Benefits:

Our benefits are designed to ensure our employees feel taken care of and are proud to be a part of the Valarian team. We are committed to consistently enhancing our benefit package, taking into account the overall well-being and needs of our teammates. Here are the key benefits accessible to all employees at Valarian Technologies:

Equity – because you have the right to own what you’re building

A competitive salary – because we value your unique skills

Employer pension contributions – because you deserve a secure future

Private health insurance - because your health is important to us

Hybrid work setup – because everyone has different needs

Rewarding company retreats and meetups that respect your work/life balance – because we love getting to know each other!

Life at Valarian

Our culture is built on inclusivity, compassion and flexibility – we want everyone to be empowered to achieve their goals at Valarian.

The work we do is vital, but so are the connections that make it happen. We thrive on the shared energy, spontaneous conversations, and mutual trust built when we spend time together. We operate on a hybrid model, gathering in our London office 3 days a week to support one another and collaborate.

Source: Valarian Technologies Limited careers (Lever)

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