Senior Full Stack Engineer - Team Web in London

Fin is the AI Customer Agent company on a mission to help businesses provide perfect customer experiences. Our AI Agent Fin is the highest-performing AI Customer Agent on the market today, enabling businesses to deliver impeccable, always-on customer support across the customer journey – from service, to sales, to ecommerce. Powered by our own AI models, Fin resolves complex customer issues end-to-end across every channel, with minimal set-up and integration.

Founded in 2011, Fin became one of the fastest growing companies and remains one of the largest private software companies in the world with nearly 30,000 global businesses using our products to transform their customer support. Driven by our core values, we push boundaries, build with speed and intensity, and relentlessly deliver incredible value to our customers.

What’s the opportunity? Our company website is the centerpiece of our brand — the public source of truth about Fin's products and the number one driver of leads for our demand generation team. Fin.ai sits at the intersection of awareness, product marketing, demand, and support, requiring robust, performant, and reliable infrastructure as much as polished user-facing interfaces. We’re looking for a Senior Full Stack Engineer to join Team Web, who is passionate about crafting intuitive front-end experiences and building the backend systems and tools that power them. You’ll play a key role in shaping the future of our website across the full stack, from UI to infrastructure, while collaborating with product marketers, designers, and engineers across the business.

What will I be doing?

• Design, build, and maintain end-to-end web solutions — from modern UIs to backend services, APIs, and infrastructure.
• Collaborate with design, brand, marketing, and content teams to deliver seamless, performant experiences across web and mobile.
• Develop backend logic and APIs, manage data flows, and implement systems that integrate with third-party platforms.
• Optimize website performance by applying best practices in front-end development, including lazy loading, and efficient asset management.
• Set up and manage infrastructure using tools like Vercel, AWS, Cloudfront, Terraform, and CI/CD pipelines (e.g., CircleCI).
• Implement and maintain web analytics, and support A/B testing for data-driven decisions.
• Stay current with emerging technologies and trends to continually improve our development processes and user experience.
• Be comfortable writing backend software.
• Build using the best tools in the industry.

What skills do I need?

• 8+ years of experience in full stack development, with expertise in JavaScript, HTML, and CSS.
• Expert in front-end frameworks such as React, Next.js, Tailwind.
• Experience in CMS platforms (such as Contentful and Sanity) and marketing tools (e.g. Google Tag Manager, Marketo).
• Experience in CI/CD tools (such as CircleCI) to streamline and automate development workflows.
• Familiarity with infrastructure as code tools such as Terraform, and cloud platforms like AWS (Vercel, CloudFront, S3, etc.).
• Experience with A/B testing and familiarity with analytics tools to drive data-informed design and development decisions.
• Knowledge of performance optimization techniques and best practices for fast-loading, responsive websites.
• Experience in writing tests for front-end components, with familiarity in testing frameworks (e.g., Jest, Mocha, Cypress).
• Strong problem-solving skills and the ability to work independently and as part of a team.
• Bachelor’s degree in Computer Science, Software Engineering, or a related field (or equivalent practical experience).

Benefits

We are a well treated bunch, with awesome benefits! If there’s something important to you that’s not on this list, talk to us!

• Competitive salary and equity in a fast-growing start-up.
• We serve lunch every weekday, plus a variety of snack foods and a fully stocked kitchen.
• Regular compensation reviews - we reward great work!
• Pension scheme & match up to 4%.
• Peace of mind with life assurance, as well as comprehensive health and dental insurance for you and your dependents.
• Flexible paid time off policy.
• Paid maternity leave, as well as 6 weeks paternity leave for fathers, to let you spend valuable time with your loved ones.
• If you’re cycling, we’ve got you covered on the Cycle-to-Work Scheme. With secure bike storage too.
• MacBooks are our standard, but we also offer Windows for certain roles when needed.

Policies

Fin has a hybrid working policy. We believe that working in person helps us stay connected, collaborate easier and create a great culture while still providing flexibility to work from home. We expect employees to be in the office at least three days per week. We have a radically open and accepting culture at Fin. We avoid spending time on divisive subjects to foster a safe and cohesive work environment for everyone. As an organization, our policy is to not advocate on behalf of the company or our employees on any social or political topics out of our internal or external communications. We respect personal opinion and expression on these topics on personal social platforms on personal time, and do not challenge or confront anyone for their views on non-work related topics. Our goal is to focus on doing incredible work to achieve our goals and unite the company through our core values.

Fin values diversity and is committed to a policy of Equal Employment Opportunity. Fin will not discriminate against an applicant or employee on the basis of race, color, religion, creed, national origin, ancestry, sex, gender, age, physical or mental disability, veteran or military status, genetic information, sexual orientation, gender identity, gender expression, marital status, or any other legally recognized protected basis under federal, state, or local law.