Senior Software Engineer (Acquisition) in London

Fresh Food, Happy Dogs. We believe dogs deserve the healthiest, most natural and tastiest meals - with none of the nasties. That’s why we make FRESHly prepared food, cooked just like you would at home and delivered direct to our customers in perfect portions. As a B-Corp certified company, you’re joining a sustainable business that genuinely cares about our people, our products and our impact on the planet. Our goal is simple: to help dogs live healthier, happier, and longer lives, while leaving humans smiling after every interaction.

The job: As a Senior Software Engineer in the Acquisition Squad, you will be the driving force behind the key application and web development projects that directly fuel our growth. You will work closely with product managers, designers, growth marketers, and fellow engineers to build features and products that optimise our signup funnels, referral loops, and landing pages to delight prospective customers.

Architecture & Delivery: Contribute to the architecture and development direction of the squad to ensure high-quality, maintainable, modular, and reliable code is shipped across our acquisition stack. Heavily Backend-Weighted: Your day-to-day focus will be heavily centered on our backend infrastructure (Ruby on Rails, PostgreSQL, GraphQL) to manage discount APIs, optimise session architectures, and support core functionality. We have a dedicated team of frontend experts who own our client-side technologies, though a willingness to collaborate across the stack is always welcome.

Marketing & Tracking Infrastructure: Partner closely with our Growth Marketing teams to maintain and optimise third-party tracking integrations. You will help manage server-side data collection, analytics event tracking, and cookie compliance, ensuring we eliminate single points of technical knowledge risk within the squad.

Engineering Culture: Learn about and champion best practices in code, systems architecture, and engineering processes while actively elevating those around you through pair programming, mentoring, and code reviews.

What we're looking for:

• Backend Expertise: Significant commercial experience in a senior engineering role with deep, production-grade familiarity with Ruby on Rails (But we are open to other OOP languages i.e Python) and PostgreSQL.
• A/B Testing Knowledge: Strong familiarity and hands-on experience implementing structured A/B testing methodologies to drive core business metrics.
• Autonomous Communication: The ability to work independently, communicate directly with downstream marketing and product stakeholders, and articulate technical/architectural decisions clearly without needing intermediaries.
• Growth & Commercial Mindset: An understanding of how backend engineering and system performance directly impact core business metrics, user tracking, and conversion rates.
• Dog-Centric: Completely obsessed with dogs!

Nice to Haves:

• Frontend Agility: Experience with React and TypeScript (if you want to flexibly pitch in on our digital onboarding stack alongside our frontend experts).
• Tracking & Analytics Tools: Experience with or exposure to third-party tools like Segment, Google Tag Manager (GTM), Meta Pixel, Google Ads, or Amazon Advertising.
• Modern Web Architectures: Familiarity with GraphQL, Storyblok (our CMS platform), and Vercel deployment workflows, alongside any exposure to Next.js.
• Domain Background: Prior experience in fast-paced B2C/B2B startup environments, subscription models, or international e-commerce platforms.

The interview process: Initial call with your dedicated Talent Acquisition Partner, carried out remotely. Take home task via Coderbyte Technical Interview Behaviours interview and Leadership Interview. We usually expect our interview process to take 3-5 weeks, end to end.

Our benefits:

• 25 days holiday (plus 8 bank holidays) and an additional day for every year of service up to 5 years
• 5 additional, paid 'paws' days off per year dedicated to your learning, development or personal wellbeing.
• Hit pause when you need it most
• £500 personal learning & development budget to sharpen your skills
• A significant discount on our Fresh food, to keep your own dogs as healthy as our customers
• Enhanced parental leave
• Flexible core working hours
• Cycle to work scheme
• Pension with NEST
• Private Medical Insurance with Vitality
• Private Dental Insurance with Bupa
• Paid time off for fertility treatments and pregnancy loss
• Paid sabbaticals for squad members with 5 or more years service at Butternut
• Discounted gym access through MyGymDiscounts
• Lots of office dogs (Ajax, Peggy, Chief, Louis, Hansen, Winnie and many more….)

Important things to note: We recommend getting your application in as soon as possible. We reserve the right to close the role early. Our team thrives on collaboration and whilst this role is being offered remotely you are also able to join us in our West London Office. We’re in 3 days a week (Monday, Wednesday, and Thursday). We’re a small (but mighty!) recruitment team. We aim to respond to everyone personally, but if we’re flooded with brilliant applications, we may need to close the role early. We appreciate your patience while we review applications. For this specific role, we’re unable to offer visa sponsorship, so you’ll need the right to work in the UK.

We believe in a seat at the table for everyone. Butternut Box is an equal opportunity employer. We believe that to make the best food for all dogs, we need a team that represents all humans. We celebrate different nationalities, backgrounds, experiences and perspectives. We are specifically committed to increasing representation from underrepresented groups. We want a strong, diverse team built from different identities and lived experiences. We’re not perfect, but we are dedicated to the ongoing work of building an inclusive, supportive place where you can do the best work of your career.