Senior Director of Engineering

Job Context Big Change  is at an inflection point. As a pioneer of AI-powered field service software now serving over 250,000 users worldwide, we're not done making big change. We've just launched Big Change Lightning — an AI intelligence layer that deploys autonomous agents across field service operations — and we need a Senior Director of Engineering to lead the teams building what comes next.

Headquartered in Leeds and part of the global Simpro Group — one of the largest field service software networks in the world — Big Change has been transforming how trades and field service businesses operate since 2013. Our platform connects jobs, people, and performance across plumbing, HVAC, fire & security, facilities management, electrical contracting, and more.

Trusted by over 2,200 high-growth businesses, we've processed billions in invoiced work and scheduled tens of millions of jobs. We've featured multiple times on the Sunday Times Tech Track 100, and we're just getting started with AI.Big Change Lightning represents the next chapter: AI agents that act as virtual business partners, trainers, documentation specialists, and customer success functions — delivering the headcount the economics never previously supported.

The Role This is a senior in-person leadership position based at our Leeds HQ. You'll lead the engineering organisation responsible for Big Change's full product suite — from the legacy monolith to our rapidly evolving microservices platform and mobile applications — while embedding an AI-First engineering culture that makes every engineer more capable, every delivery faster, and every customer outcome stronger.

You will report to executive leadership and be a key voice in shaping the technical future of one of the UK's most recognised field service technology businesses.

Location:

Leeds (LS15), on-site.

What You’ll DoTeam Leadership Build, mentor, and inspire high-performing engineering teams. Drive a culture of ownership, craft, and continuous improvement from squad level to organisational level. Develop engineering managers and create clear career pathways for individual contributors and leaders alike.

AI-First Culture Champion the integration of AI into every layer of how we build — from developer tooling and CI/CD intelligence to the AI agents at the heart of Big Change Lightning. This isn't about adopting tools; it's about fundamentally changing how engineers work and what they can achieve.

Engineering Strategy Partner with Product and the C-suite to shape the technical roadmap. Balance velocity on new capabilities with architectural health across a hybrid legacy and modern stack. Translate business goals into clear engineering priorities.

Platform Evolution Oversee the continued migration from AWS EC2 monolith toward AWS EKS microservices. Make the architectural decisions that protect reliability and security while enabling rapid innovation and scale.

Delivery Excellence Own engineering velocity, quality, and predictability. Build the processes and metrics that let teams move fast without creating tomorrow's technical debt. Hold the bar on engineering standards without becoming a bottleneck.

Hiring & Talent Attract and retain exceptional engineering talent in Leeds and beyond. Make Big Change the kind of engineering organisation that people choose over the obvious alternatives. Be the reason great engineers want to stay.

What You’ll Bring Proven track record leading high-performing engineering teams at scale — you've built, grown, and developed engineering organisations, not just managed them.

Genuine conviction about AI in engineering — you've moved teams beyond AI as a curiosity to AI as a core capability multiplier.

Strategic technical depth - you can engage credibly with senior engineers on architecture without needing to be the smartest technologist in the room.

Experience with SaaS product companies you understand how engineering decisions compound into product and commercial outcomes.

Comfort with complexity — you've navigated hybrid environments combining legacy systems and modern platforms, and you've made that transition well.

Strong presence and communication — you lead in…