Senior AppSec Engineer

Senior AppSec Engineer
Department: Consultancy
Employment Type: Full Time
Location: Remote

Description

The Role

Are you passionate about building security into software from the ground up? We’re looking for a Senior Application Security Engineer to take charge of strengthening and evolving security across our Loyalty division.

In this role, you won’t just identify risks you’ll lead the charge in transforming how secure software is built, working side-by-side with engineering and product teams to make security an intrinsic part of everything we deliver.

What you’ll be doing

Own and drive application security strategy, influencing key security metrics and outcomes

Embed secure-by-design principles into every stage of the development lifecycle

Partner with engineers and product teams to elevate security awareness and capability

Introduce and optimise automated security controls within CI/CD pipelines

Lead threat modelling and secure design discussions, shaping decisions around critical areas like authentication and data protection

Ensure security tooling (SAST, DAST, SCA) is effective, scalable, and delivering real value

Oversee and enhance testing initiatives including penetration testing, scanning, and bug bounty programmes

Act as a trusted advisor to engineering teams triaging issues and guiding practical remediation

Contribute to security standards, documentation, and audit readiness

Champion a strong, proactive security culture across the organisation

Knowledge Skills & Abilities

A background in software engineering with a security-first mindset

Strong knowledge of modern web and API vulnerabilities (OWASP Top 10 and beyond)

Hands-on experience with automation, scripting, and integrating security into CI/CD workflows

Familiarity with security tooling such as SAST, DAST, and SCA

Experience working in cloud-native environments (AWS), microservices, and containerised systems

Confidence in reviewing architecture, leading threat modelling, and influencing secure design decisions

Excellent communication skills, ablility to engage, educate, and inspire engineering teams

Behaviours

An open and genuine communicator

Able to take responsibility for your actions

Always learning and wanting to improve

Takes responsibility for own development

Love what you do

Value and support your team

Embrace who you are

Open minded and willing to explore new ideas

What We Offer
We value our team and to attract exceptional people, we offer an excellent package! In 2023, 2024 and 2025 we were recognised as one of the Best Workplaces in Tech by Great Place To Work UK, the global authority on workplace culture.

As a Leighton employee you can look forward to:

A competitive salary this will be dependent on experience.

A contributory pension scheme

Private healthcare

25 days annual leave, plus bank holidays and the opportunity to buy or sell holiday

A flexible approach to working hours

Continuous personal development, career path and training

And more....