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- Tasks: Revolutionise customer lifecycle marketing and build smart CRM systems using AI.
- Company: Join Fleek, a fast-growing startup transforming the secondhand fashion industry.
- Benefits: Competitive salary, dynamic work environment, and opportunities for personal growth.
- Other info: Collaborative culture with a focus on ownership and diversity.
- Why this job: Make a real impact in sustainability while working with cutting-edge technology.
- Qualifications: Experience in AI, CRM systems, and a passion for innovation.
The predicted salary is between 60000 - 80000 £ per year.
Can you help us fix the world's most broken supply chain? The fashion industry produces over 100 billion garments a year. 60% end up in landfill, not because people don't want these clothes, but because the supply chain for getting secondhand fashion from donation to resale is completely offline, manual, and broken. Fleek is fixing this. Our mission is to make secondhand the first choice. We are building the infrastructure powering the global secondhand clothing trade, through a B2B marketplace and the AI systems digitising the supply chain behind it.
Through Fleek, vintage stores, online resellers, and retail buyers source graded secondhand inventory directly from wholesalers and rag houses across multiple countries. Our key enabler is FleekSort, an AI model fine-tuned on secondhand fashion, that can grade, price, and categorise items with just a photo, turning what has historically been an opaque and manual trade into a structured, searchable, and tradable global inventory layer. Since 2022, we have saved 9 million items from landfill and tripled in size year-on-year. We have raised ~$50M from a16z, Y Combinator, Burda Principal Investments, HV Capital, and others, and have recently closed our Series B. Our advisors and private investors include operators behind Depop, Shopify, and Postmates. Today, we serve thousands of resellers and retailers across the UK, Europe, and the US. With the secondhand fashion market projected to reach $350B by 2027, Fleek is building the AI-native operational and financial backbone for secondhand commerce globally.
We are looking for people who want to build something that matters, and move fast doing it. Sound good? Keep reading.
About the Role
We are looking for a deeply technical, highly innovative Full-Stack Growth Builder to reinvent how customer lifecycle marketing drives growth at Fleek. You will architect the entire system, from data to strategy to execution, and treat AI as your default toolkit, not a nice-to-have.
You will design smart CRM systems that determine who to contact, when, through which channel, and with what message, using real-time user signals and context. You will build rigorous experimentation frameworks to quantify the true incremental impact of lifecycle messaging and prevent over-attribution. And you will lead the adoption of AI-powered content generation and personalisation, balancing scale with quality and relevance.
This is a marketplace scaling from thousands to tens of thousands of active buyers. The data infrastructure is being built in real time. If you get energy from building systems that learn, proving what actually works, and shipping at speed, this is the role.
What Makes You a Fleek Growth Builder?
- Systems Architect: You do not just run campaigns. You design adaptive systems that decide who to message, when, through which channel, and with what content, and that get smarter over time.
- AI-Native: You use AI as your default toolkit. Content generation, personalisation, segmentation, decisioning. You have built or implemented AI-driven systems, not just read about them.
- Experimentation Obsessed: You think deeply about incrementality, holdouts, causal inference, and marginal impact. You have caught campaigns that looked good on surface metrics but had no real value.
- Commercially Wired: You connect lifecycle outputs to business outcomes. You think in activation rates, retention curves, LTV, and revenue impact, not just open rates and clicks.
- Comfortable with Ambiguity: Fleek's growth data is complex and evolving. You thrive when the data is messy, the tracking is not perfect, and you need to find the answer anyway.
- Action-Oriented Communicator: You translate complexity into 'here is what to do.' Your stakeholders never have to guess what the data means.
- Startup Pace: You have worked in environments where speed matters, where you ship systems that drive same-week decisions, and where velocity is a competitive advantage.
What You'll Do
- Own the Consumer Lifecycle: Take full ownership of lifecycle strategy from onboarding and activation through engagement, retention, reactivation, and monetisation.
- Build Smart CRM Systems: Design and continuously improve systems that determine who to contact, when, through which channel, and with what message, using real-time user signals and context.
- Run Rigorous Experiments: Build and maintain experimentation frameworks to quantify the true incremental impact of lifecycle messaging. Use holdouts, lift tests, and causal inference to prevent over-attribution.
- Lead AI-Powered Personalisation: Drive the adoption of AI for content generation, personalisation, and decisioning. Balance scale with quality and relevance.
- Analyse and Surface Opportunities: Regularly analyse performance and experimental results to surface high-impact opportunities for activation, retention, and revenue.
- Manage Frequency and Trust: Establish best practices around frequency, fatigue management, and long-term user trust. Users should experience Fleek as relevant and well-timed, never noisy or generic.
- Build Reseller Tooling: Help build tooling for resellers end-to-end to drive retention and stickiness, such as cross-listing tools to go from Fleek to consumer marketplaces.
- Stay Ahead: Stay ahead of developments in lifecycle marketing, experimentation, and AI. Turn new ideas into production-ready systems.
- Use AI to Move Faster: Automate workflows, speed up analysis, and surface insights before anyone asks. You think about your role as a 10x-er through the lens of AI.
What You Bring
- Hands-on AI and automation experience. You have applied AI to content generation, personalisation, segmentation, or decisioning within CRM systems. Not theoretical, production.
- Experience designing adaptive systems. Rules-based, algorithmic, or hybrid decisioning systems that optimise messaging, prioritisation, timing, and frequency.
- Strong product intuition. You balance short-term optimisation with long-term customer trust and experience.
- Startup or scale-up experience. You have worked in environments with fast cycles, evolving data infrastructure, and high ownership.
Nice to Have
- Experience with Python or R for statistical modelling and analysis.
- Familiarity with data warehousing tools (BigQuery, Snowflake, dbt).
- Experience building CRM/lifecycle infrastructure from scratch.
- Background in building tools or internal products (not just campaigns).
Ready to build the lifecycle engine behind one of the fastest-growing marketplaces in Europe? If you want to architect systems that learn, prove what actually works, and ship at speed with a world-class team, we would love to hear from you.
How We Work
Fleek is an in-office company. We believe the best work happens when people are together, the quick decisions, the cross-functional energy, the ability to solve problems in real time. Most of the team works from our London HQ 3-4 days a week. We are not prescriptive about it. Performance and trust matter more than attendance. We hire adults and treat them accordingly.
The Practicalities
- Location: London HQ, Commercial St, E1 (Liverpool St / Aldgate East)
- Work model: In-office, typically 3-4 days per week.
- Level: Senior
- Stage: Post-Series B, hyper-growth
- Team: 100+ across London, India, and Pakistan (~20 in London office)
- Culture: High ownership, non-hierarchical, fast-moving. Founder-led with strong opinions loosely held.
Our Values
- Dream Big and Disrupt Yourself: Push the most ambitious version of what you are building. Step out of your comfort zone. Nothing is out of reach.
- Absolute Ownership: The buck stops with you. Drive initiatives to completion. Experiment, learn, persevere. The job is not done until the job is done.
- Curiosity Leads the Way: Do not accept anything at face value. Ask questions you do not know the answer to. That is how you innovate.
- Talk to the Customer: Deeply understand their challenges, motivations, and ambitions. Every decision starts with the customer at the centre.
- Embrace Diversity: A global team building for a global supply chain. Bring your authentic self and embrace the diversity of everyone you encounter.
Full Stack Growth Builder in London employer: Fleek
Contact Detail:
Fleek Recruiting Team
StudySmarter Expert Advice 🤫
We think this is how you could land Full Stack Growth Builder in London
✨Tip Number 1
Network like a pro! Get out there and connect with people in the industry. Attend events, join online forums, and don’t be shy about reaching out on LinkedIn. You never know who might have the inside scoop on job openings or can put in a good word for you.
✨Tip Number 2
Show off your skills! Create a portfolio or a personal project that highlights your expertise in full-stack development and AI. This is your chance to demonstrate what you can do beyond just a CV. Share it on your social media or even better, apply through our website and include it!
✨Tip Number 3
Prepare for interviews by practising common questions and scenarios related to lifecycle marketing and AI systems. Think about how you would tackle real-world problems at Fleek. We want to see your thought process, so be ready to discuss your ideas and solutions!
✨Tip Number 4
Follow up after interviews! A quick thank-you email can go a long way. It shows your enthusiasm for the role and keeps you fresh in the interviewer's mind. Plus, it’s a great opportunity to reiterate why you’re the perfect fit for the Full Stack Growth Builder position.
We think you need these skills to ace Full Stack Growth Builder in London
Some tips for your application 🫡
Show Your Passion: When writing your application, let your enthusiasm for the role and our mission shine through. We want to see that you genuinely care about fixing the broken supply chain in the fashion industry and are excited about the impact you can make.
Tailor Your Experience: Make sure to highlight your relevant skills and experiences that align with the job description. We’re looking for someone who can design adaptive systems and use AI as a toolkit, so be specific about how your background fits these needs.
Be Clear and Concise: Keep your application straightforward and to the point. We appreciate clarity, so avoid jargon and focus on communicating your ideas effectively. Remember, we want to understand what you bring to the table without sifting through fluff.
Apply Through Our Website: Don’t forget to submit your application through our website! It’s the best way for us to receive your details and ensures you’re considered for the role. Plus, it shows you’re keen to engage with us directly.
How to prepare for a job interview at Fleek
✨Know Your Stuff
Before the interview, dive deep into Fleek's mission and the secondhand fashion market. Understand how AI is transforming supply chains and be ready to discuss specific examples of how you've used AI in your previous roles. This shows you're not just interested in the job, but also passionate about the industry.
✨Showcase Your Systems Thinking
Be prepared to talk about your experience designing adaptive systems. Bring examples of how you've built or improved CRM systems that optimise messaging and engagement. Highlight your ability to connect lifecycle outputs to business outcomes, as this is crucial for the role.
✨Experimentation is Key
Fleek values a rigorous approach to experimentation. Be ready to discuss frameworks you've implemented to measure the impact of marketing strategies. Share specific instances where you’ve used holdouts or causal inference to derive insights, demonstrating your obsession with incrementality.
✨Communicate Clearly and Confidently
During the interview, focus on translating complex ideas into actionable insights. Practice explaining your past projects in a way that’s easy to understand. This will show that you can communicate effectively with stakeholders, which is essential for driving initiatives at Fleek.