Posted May 15, 2026
Mast is on a mission to make complex lending simple. The UK's specialist lending market is underserved by technology, with legacy systems that can't handle the nuance of complex income, niche products, or the broker workflows that specialist lenders rely on. We're building modern, cloud-native lending technology, purpose-built for specialist lenders, that helps them process more applications in less time, reach decisions faster, and deliver better experiences for brokers and borrowers. We're pioneering the use of AI in mortgage origination, building it into the platform from the ground up rather than bolting it onto legacy architecture.. We work with regulated lenders across the UK, have a 100% delivery track record, and are building a high-performance team where everyone has real ownership and direct impact. We're looking for a Platform & Security Engineer to help scale and secure the Mast platform as we continue to grow. This role combines platform engineering, cloud infrastructure, security, reliability, observability, operational resilience, and compliance. You'll work closely with the Head of Engineering to improve developer experience, modernise infrastructure, strengthen our security posture, and ensure our systems remain reliable and resilient as we onboard more clients and ship more features. This role is suited to an experienced engineer comfortable owning infrastructure, security, reliability, and operational resilience across production systems in a fast moving startup environment. ## Responsibilities
Cloud & Platform
Security & Compliance
System Reliability & Observability
Developer Experience (DevEx)
Location: London or UK Remote
Salary: £90,000 to £100,000 + Stock Options
Benefits
Mast. ##### ABOUT US
Mast is a high-performance team of engineers and lending experts building the future of specialist lending technology. We value radical honesty, transparency, and speed. We hire exceptional people, expect a lot from each other, and offer real ownership, fast growth, and the chance to shape an industry.
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