Senior Software Engineer

Relay is fundamentally reshaping how goods move in an online era. Backed by Europe’s largest-ever logistics Series A ($35M), led by deep-tech investors Plural (whose portfolio spans fusion energy and space exploration), Relay is scaling faster than 99.98% of venture-backed startups. We're assembling the most talent-dense team the logistics industry has ever seen Relay’s Mission is to free commerce from friction. Today, high delivery costs act as a hidden tax on e-commerce, quietly shaping what can be sold online and limiting who can participate. We envision a world where more goods move more freely between more people, making the online shopping experience seamless and accessible to everyone. THE TEAM • ~110 people, more than half in engineering, product and data • 45+ advanced degrees across computer science, mathematics and operations research • Thousands of data points captured, calculated, analysed and predicted for every single parcel we handle • An intellectually vibrant culture of first‑principles thinking, tight feedback loops and relentless experimentation Work Alongside Industry Leaders Diego Protas – Director of Engineering Diego, an expert in distributed systems and hardware architecture, merging physical computing with enterprise-scale infrastructure. Previously directing teams of 170+ engineers at Mercado Libre and orchestrating large-scale ML-based inference at Meta. At Relay, Diego’s infectious enthusiasm and hands-on leadership are redefining the boundaries of speed and reliability. Tech Stack Highlights - Python, Rust and TypeScript - we keep things simple but use the right tool for the job - Cross-platform Flutter apps with a deep focus on user experience - Cloud-native on GCP with extensive use of BigQuery and Cloud Run - Extensive use of ML modelling and LLM inference - no gimmicks here, this is our daily routine - Emerging tech integrations, including robotics and IoT-powered operations The Opportunity As a Software Engineer at Relay, you'll: - Own challenging, impactful problems end-to-end, from routing algorithms to real-time optimisation services and intuitive operational tools. - Collaborate closely with top engineers, data scientists, and product leaders in a highly autonomous and impact-driven environment. - Regularly ship production-quality code weekly—and often daily—seeing your work directly impact Relay’s growth. - Create incredible product experiences powering the fastest-growing e-commerce platforms, including Vinted, TikTok, and Temu, impacting millions of users worldwide. Fast and Focused Hiring Process 1. Talent Acquisition Interview - 30 min 2. API Integration Interview - 1 hour 3. Technical Interview - 2 hours 4. Operating Principles & Impact - 1 hour 5. Decision and offer within 48 hours; our process mirrors our pace of work, typically completed in a week. Compensation, Benefits & Workplace - Generous equity, richer than 99% of European startups, with annual top-ups to share Relay’s success. - Private health & dental coverage, so comprehensive you’d need to be a partner at a Magic Circle law firm to match it. - 25 days of holidays - Enhanced parental leave. - Located in Shoreditch, our office set-up enables the kind of in-person interactions that drive impact. We work 4 days on-site, with 1 day remote. - Hardware of your choice. - Extensive perks (gym subsidies, cycle-to-work, Friday office lunch, covered Uber home and dinner for late nights, and more). Who Thrives at Relay? - Aim with Precision: You define problems clearly and measure your impact meticulously. - Play to Win: You chase bold bets, tackle the hard stuff, and view constraints as fuel, not friction. - 1% Better Every Day: You believe that small, consistent improvements lead to exponential growth. You move quickly, deliver results, and learn from every experience. - All In, All the Time: You show up and step up. You take ownership from start to finish and do what it takes to deliver when it counts. - People-Powered Greatness: