Principal Software Engineer (Contract)

Collinson; London; On-site; GBP 125,000 - 150,000; Full time

Job description

Company

Collinson is a global loyalty and benefits company.

We use our expertise and products to craft customer experiences which enable some of the world’s best known brands to acquire, engage and retain the most demanding and choice-rich customers. In particular, our unique expertise and insight into high earning, frequent travellers allows us to create products and solutions for our clients that inspire greater customer engagement to drive more profitable relationships, enrich their travel experiences, protect what matters and assist in in times of need.

While specialising in Financial Services, Travel and Retail, we also support clients in multiple sectors. We have worked with over 90 airlines, 20 hotel groups and more than 600 financial institutions and banks, with clients including Accor Hotels, Air France KLM, American Express, British Airways, Cathay Pacific, Diners Club, Mandarin Oriental, Mastercard, Radisson Hotel Group, Sephora, Visa and Vhi.

We take our 30 years’ experience working with these kinds of household names in over 170 countries, and help our clients to deliver the smarter experiences it takes to differentiate their propositions, and help them win deeper devotion with their customers.

Collinson is a privately-owned entrepreneurial business with 2,000 passionate people working in 20 locations worldwide. Our solutions include Priority Pass, the world’s best known airport experiences programme, while we are also the trusted partner behind many of the leading financial services, airline and hotel brand’s reward programmes and loyalty initiatives.

The Role

As a Principal Engineer, you’ll be leading the technical direction for a recently kickstarted greenfield initiative, designing and building systems from the ground up. This is an opportunity to shape the foundations of something new, modern, and built the right way.

You’ll set the architectural vision, make high-impact technical decisions, and guide multiple squads towards building scalable, well-engineered software. This is a hands-on role, where you’ll be designing, coding, and solving the toughest technical challenges.

With a modern cloud-native stack and the freedom to approach problems with fresh thinking, you’ll be working at the cutting edge - embedding AI, automation, and best-in-class engineering practices into everything we build.

If you enjoy building new things, defining technical strategy, and working with highly capable teams, this role offers the space and responsibility to do just that.

Key Responsibilities

• Technical Leadership - Own the technical strategy for your pillar, guiding multiple squads towards high-quality, scalable, and well-architected solutions.
• Hands-On Architecture & Development - Lead the design and development of complex, high-scale systems. This means writing real code, building proof-of-concepts, and diving into problem-solving.
• Engineering Consistency - Ensure teams within your initiative follow engineering best practices, write clean and maintainable code, and maintain high standards in security, performance, and observability.
• Mentorship & Coaching - Support and upskill Lead Engineers and squad engineers, helping them grow into their full potential.
• Modern Software Practices - Champion SOLID principles, automated testing, and CI/CD best practices, ensuring deployments are fast, safe, and seamless.
• Observability & Performance - Help teams build highly observable systems using DataDog and other tools, making sure we can see and fix issues before they impact users.
• Collaboration - Work closely with Product Managers, Senior Product Directors, Delivery Managers, and Engineering Managers to ensure our technical approach aligns with business needs.
• Infrastructure & Deployment - Be comfortable working with GitHub Actions, Terraform, Kubernetes, and AWS to ensure our systems are resilient and scalable.
• AI & Future Tech - We want to push the boundaries of AI-driven development - if you have ideas on how to embed AI into our engineering processes, you’ll have the space to explore them.

Knowledge, skills and experience required

• Tech stack - We use TypeScript (Node.js & React), AWS (EKS, Lambda, Aurora RDS), Kubernetes, and GraphQL. You’re comfortable with all of these, and have extensive knowledge of JavaScript more generally, the AWS ecosystem, and running containerised applications.
• Past Experience - You have proven experience designing large, distributed, data-driven systems in the cloud, and you’ve ran an engineering team/squad previously.
• Test-Driven Development – You're very familiar with testing frameworks such as Jest and Pact.
• Architecture & Problem Solving - You can architect a system that scales, handles high throughput, and integrates seamlessly with a complex ecosystem.
• CI/CD & Infrastructure as Code - You’ve deployed production systems using Terraform and Helm, and have experience with GitHub Actions as a CI/CD platform.
• Observability Mindset - You believe in measuring everything. You’ve worked with DataDog (or similar) to ensure teams have visibility into system health.
• Software Craftsmanship - You write high-quality, maintainable code, champion SOLID principles, and understand when to be pragmatic vs. when to be purist.
• Mentorship & Leadership - You’ve mentored engineers at all levels, providing guidance, reviewing designs, and ensuring teams stay on the right track.