Changing the world of pet food for good We’re Tails.com, a dog food subscription company with a big difference. We create truly tailored food for each and every dog we serve. We start by asking people a few simple questions about their dog. Then we use that information to create their dog’s unique Tails.com recipe – so their dog gets exactly the nutrition they need, in the taste they love, delivered to their door every month. It’s clever stuff. We’ve got bold plans. Having created an entirely new category in pet food, we’re now scaling fast in the UK and Europe – backed by Purina, one of the world’s largest pet food companies. You’ll join a bunch of smart people working towards the same goals – and a bunch of smart-ish dogs, all working on their own thing. Together, we’ll change the world of pet food for good. Engineer Scalable Systems and Lead Hands-On Innovation at Tails.com As a Principal Engineer, you’ll play a critical role in shaping and building the systems that power personalised nutrition for dogs across the UK and Europe. Working across squads, you’ll combine hands-on coding with architectural thinking to solve complex problems and deliver scalable, secure solutions. Partnering closely with our Software Architect, Product, and Engineering teams, you’ll lead technical decision-making on strategic initiatives, guide engineers through system evolution, and contribute directly to the codebase. Your impact will be felt across domains as you unblock teams, model engineering excellence, and help us build a platform ready for the next stage of growth. Together, we’ll deliver smart, sustainable tech that transforms the future of pet care — one dog at a time. Build our brand We’re building an international brand, fast. We set ambitious goals. We challenge and support each other in equal measure. At the pace we’re moving, we prefer to test ideas and learn quickly rather than spend months building a business case. That means we celebrate when things go right, and we learn when things go wrong. Sound like a team you want to join? Here’s how you’ll make a difference: The role We’re looking for a Principal Engineer to play a key role in shaping the technical future of Tails.com. This is a high-impact individual contributor role that blends deep architectural thinking with hands-on engineering and cross-squad collaboration. Reporting to our Software Architect, you’ll play a critical role in shaping and applying our evolving architectural vision. You’ll work holistically across multiple squads, ensuring scalable architecture is consistently applied and adapted to the needs of complex, high-impact projects. You’ll be deployed into squads to support our most strategic initiatives – contributing to solution design, guiding technical direction, and writing production-ready code alongside your teammates. You’ll act as a trusted partner to product and delivery teams, helping shape solutions that are technically sound and aligned to our business strategy. Our core stack is built in Python, and we’re looking for someone who can both design for and work hands-on within this environment. You will be responsible for: Architecture & technical strategy Lead the design of scalable, secure, and performant systems across domains Provide architectural direction and challenge assumptions during solution design Contribute to our technical strategy and help translate it into actionable roadmaps Partner with squads to align on design principles and promote shared patterns Act as a trusted partner in platform and product evolution, aligning engineering decisions with business needs Engineering excellence & enablement Write and review production-grade code in Python, contributing directly to the systems you help design Champion best practices across testing, CI/CD, observability, security, and reliability Identify areas of technical debt and propose strategic improvements Drive initiatives to improve developer experience and reduce workflow friction Collaborate with Platform and DevOps engineers to level up tooling and infrastructure Contribute to shaping technical standards, documentation, and review processes that scale Technical leadership & mentorship Mentor and challenge senior engineers and squad leads to support their growth as technical leaders Lead by example through high-quality code, technical documentation, and strong engineering practices Contribute to internal engineering forums, knowledge-sharing, and our learning culture Support the development of future technical leaders within the team Cross-functional influence Collaborate closely with Product, Delivery, and Design to ensure technical feasibility and alignment Represent Engineering in complex product or platform initiatives Support squads in identifying and mitigating risks early in the delivery lifecycle Facilitate communication across teams to ensure alignment and shared understanding The experience you will bring: Proven experience as a Principal Engineer or similar senior IC role, ideally within fast-paced, product-led environments. Hands-on experience designing and evolving complex systems at scale, ideally with a focus on Python-based platforms. Strong background in modern software architecture and distributed systems, with a passion for clean, scalable, and resilient design. Practical experience writing production-grade code, with a focus on quality, maintainability, and developer experience. Deep understanding of testing, observability, CI/CD, and security best practices in a modern engineering environment. Excellent communication and collaboration skills, with the ability to influence technical direction across squads and functions. Comfortable mentoring and supporting senior engineers and squad leads to help them grow as technical leaders. A natural problem-solver who enjoys working in ambiguous spaces and leading through complex technical challenges. A proactive mindset and a strong sense of ownership, with a bias for action and continuous improvement. What's in it for you? Competitive salary, reviewed annually Annual bonus, based on company performance Flexible core hours, giving you true work-life balance Hybrid role to ensure this role works for you 25 days of holiday (excluding bank holidays) which increases over time to a max of 27 days 9/10 day working week to enhance your wellbeing without a reduction in pay and leave allowance Optional 5 days unpaid leave and 1 paid volunteer day each year When you need a change of scenery, you can work from abroad 2 weeks every 6 months Health insurance for you, paid by Tails.com Extended maternity, paternity, shared parental and adoption pay. 6 months at 70% pay Flexible paid care leave to support immediate dependents, people close to you and pets In-house L&D team, with access to year-round courses to help drive your development 50% discount on all Tails.com What’s next? If this sounds like it matches your experience and what you’d love to do, we can’t wait to hear from you! If you’re unsure whether you fit our criteria exactly, please get in touch anyway. And because we believe that diverse teams perform better, we’d especially love to hear from you if you’re from an under-represented demographic. Here’s a taster of how our recruitment process works: Once you have applied, your CV will be reviewed by our recruitment team. If selected, you will then have a take-home coding test to assess your coding stills within Python. The next stage will be an Architecture chat with a live Tech Design session with senior stakeholders in Engineering & Architecture (1 hour). The final stage will be a People and Leadership chat with our Head of Software Engineering (1 hour). Our Commitment We’re proud to be an active equal opportunity employer. We want to give everyone a fair chance to join us in changing the world of pet food for good. We do this by conducting a structured recruitment process for all candidates, as well as actively promoting our roles to communities that are underrepresented at Tails.com. During your interview process, you’ll meet some of our team with varying levels of responsibility and experience. We want to give every candidate a fair interview process and if you need any reasonable adjustments made, please let us know.