Senior Mobile Security Developer - Contract (Inside IR35) in London

Waracle are looking for a Senior Mobile Security Developer (Inside IR35) for an exciting new 6-month initial contract joining our world-class digital technology consultancy, home to a diverse, smart, curious and ambitious community of specialists in technology-driven transformation.

We work with ambitious clients to help them solve their biggest business and customer challenges. We help our clients to innovate and create intelligent digital products and services. We thrive on complex challenges and deliver business-critical IT transformation projects, moving seamlessly from strategy, design and delivery to operations.

This is a UK-based Inside IR35 Contract role, offering the flexibility to balance your professional and personal life, with 2 days a week spent connecting with colleagues in our London office or on client site.

The Role

As a Senior Mobile Security Developer, you will define squad-level technical architecture and technical approach. You are a technical expert who ensures quality, security, and compliance across projects, driving robust and scalable solutions. This role will be pivotal in building, delivering, and driving the security of our mobile platform, while being an integral part of our full-stack mobile practice, contributing to end-to-end development and security excellence across both front-end and back-end mobile systems.

Key aspects of the role include:

• Design and Delivery of a World-Class Security Framework: Lead the design and delivery of security services, including mobile penetration testing, research, consultancy, and advisory engagements.
• Technical Strategy & Architecture: Define secure technical approaches, identify risks, and develop effective threat models and mitigation strategies.
• Strategic Planning: Translate business objectives into technical strategy and ensure technical roadmaps align with long-term client goals.
• Agile Practices: Expertise in Agile methodologies, with a focus on resolving impediments and driving adoption across teams.
• Client Engagement: Communicate effectively with clients, manage expectations, and provide practical, risk-based security recommendations.
• Continuous Improvement & Collaboration: Drive innovation, adopt emerging security practices, share knowledge, and support team success.

What you'll bring:

We are seeking a highly technical expert with a strong focus on mobile platform security. You should bring:

• Mobile Security Expertise: Strong hands-on knowledge of Android and iOS security fundamentals, common mobile threats and vulnerabilities, security architecture, controls, and mitigation techniques.
• Mobile Security Testing: Practical experience in mobile penetration testing, security assessments, threat modelling, and implementing or assessing security controls.
• Security Problem Solving: A systematic and analytical approach to identifying, investigating, and resolving mobile security issues.
• Authentication & Cryptography: Strong understanding of authentication, authorisation, cryptography, encryption, and secure design principles, with the ability to recommend appropriate cryptographic controls.
• Continuous Improvement: A proactive approach to improving security practices, tooling, controls, and ways of working.

Desirable knowledge & experience:

• Mobile Security Tooling & Analysis: Experience with reverse engineering, analysis techniques, and tools such as Burp Suite Pro, Frida, Objection, JADX, IDA Pro, Hopper, Radare, ADB, Apktool, YARA, Xcode, and Android Studio.
• Mobile Development & DevSecOps: Knowledge of Android/iOS development, secure development practices, DevSecOps tooling, testing, and automation frameworks.
• Development & Reverse Engineering: Familiarity with C, Java, Kotlin, Objective-C, Swift, JavaScript, Python or Bash, and ideally ARM/ARM64 assembly.
• Security Research: Awareness of emerging security technologies, Cloud security, and developments in mobile operating systems, APIs, tools, and security libraries.

What to expect from our hiring process:

• First Hello: An informal chat with your dedicated Talent Attraction Partner to talk about Waracle, what you want out of your next move, salary, benefits, and office hybrid working model.
• Craft Showcase: A chance to demonstrate your real-world expertise. Depending on the role, this will be a focused take-home task (capped at 2–3 hours to respect your time) or a practical presentation.
• Talking Impact: A collaborative deep dive into how you solve problems, work with others, and raise the bar, guided by our core values and competency framework.

Your Talent Attraction Partner will be in your corner through every step right up to your Welcome Ritual on day one.

We are an equal opportunities employer and welcome applications from all suitably qualified persons regardless of their race, gender, disability, religion/belief, sexual orientation or age.