Senior Backend / Platform Engineer – High-Growth SaaS Start-Up – Discrete Search – Excellent Compensation + Equity

My client, a fast-growing and well-backed technology company, is seeking multiple senior backend and platform engineers to join its London team.

This is a unique opportunity to join a high-performing, low-ego engineering culture, working on complex, real-world systems with immediate ownership and impact. The team is focused on building and scaling core backend infrastructure and internal platforms that power critical business functionality.

These roles sit at the intersection of backend engineering, distributed systems, and infrastructure, offering the chance to shape both technical direction and engineering standards within a rapidly evolving environment.

You’ll be working closely with senior leadership and a small, highly capable team, contributing to the design, build, and optimisation of systems from the ground up.

Responsibilities:

• Design and build scalable backend systems and services in a high-availability environment
• Develop and improve core infrastructure, tooling, and internal platforms used across engineering teams
• Contribute to architectural decisions and help shape long-term technical direction
• Identify and resolve performance, reliability, and scalability challenges across systems
• Work cross-functionally to support and unblock multiple engineering teams
• Improve engineering workflows, system efficiency, and overall platform robustness
• Take ownership of key systems and deliver high-impact solutions from concept to production
• Collaborate closely with stakeholders in a fast-paced, iterative development environment

Requirements:

• Strong experience building backend or infrastructure systems at scale
• Solid understanding of distributed systems, performance, and reliability
• Experience working in high-quality engineering environments (e.g. leading tech firms or high-growth startups)
• Proven ability to take ownership and deliver complex systems end-to-end
• Comfortable working in fast-moving, ambiguous environments
• Strong problem-solving skills and systems thinking
• Collaborative mindset with a low-ego, team-first approach

Nice to have:

• Experience with real-time systems, messaging, or communications infrastructure
• Exposure to modern backend languages and frameworks (e.g. Elixir or similar functional paradigms)
• Background in platform engineering, developer infrastructure, or internal tooling
• Previous experience in startup or scaling environments

What You Can Expect:

• High levels of ownership and responsibility from day one
• Direct access to leadership and influence over technical direction
• A fast-moving, collaborative, and low-bureaucracy environment
• Strong engineering culture focused on impact and execution
• Competitive compensation with meaningful equity upside
• The opportunity to build systems from the ground up, rather than maintain legacy platforms

My client is looking to move quickly for the right individuals and offers a streamlined interview process (1 week maximum)

To apply, either respond to this advert or send your CV directly to sasha.duquesne@mondrian-alpha.com