Backend Engineer

SpaceXAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge. Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity. We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company’s mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important. All employees are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates. ABOUT THE ROLE: In this role you will work on SpaceXAI's production systems that power the API. The actual team matching will happen at the offer stage. As an ideal candidate you have a good understanding of how highly scalable and reliable production infrastructure is built. You strive for perfection and listen carefully to your users in order to solve any pain points they might experience. Most of our backend infrastructure is written in Rust. So familiarity with a compiled language such as C++, Rust, or Go is highly beneficial. BASIC QUALIFICATIONS: * Expert knowledge of either Rust or C++, * Experience in designing, implementing, and maintaining reliable and horizontally scalable distributed systems, * Knowledge of service observability and reliability best practices, * Experience in operating commonly used databases such as PostgreSQL, Clickhouse, and MongoDB. PREFERRED SKILLS AND EXPERIENCE * Knowledge of Python, * Experience with Docker, Kubernetes, and containerized applications, * Expert knowledge of gRPC (unary, response streaming, bi-directional streaming, REST mapping), * Hands-on experience with LLM APIs, embeddings, or RAG patterns, * Track record of delivering user-facing software at scale. COMPENSATION AND BENEFITS: £107,000 - £262,000 GBP Base salary is just one part of our total rewards package at SpaceXAI's, which also includes equity, comprehensive healthcare and dental coverage, cash plan, income protection, life insurance, and various other discounts and perks. SpaceXAI is an equal opportunity employer. For details on data processing, view our Recruitment Privacy Notice.

AT GRADIENT LABS, WE'RE BUILDING THE AI CUSTOMER OPERATIONS PLATFORM FOR FINANCIAL SERVICES. Founded in 2023, we now work with some of the biggest names in banking and fintech. Our platform runs specialist agents, purpose-built for financial services, to eliminate manual work across customer support and back-office operations. Together, they give product and operations teams the visibility and control to trust every outcome. We're a team of builders from companies like Monzo, Wise, Mastercard, Revolut and Google. If you're excited to tackle some of the hardest problems in AI and help shape the future of customer operations, we'd love to hear from you.   🎯 HOW YOU’LL MAKE AN IMPACT This isn't a maintenance role or a feature factory. At Gradient Labs, you will own systems that matter — from the first architectural decision through to production, scale, and everything that breaks along the way. You'll work on the infrastructure that makes autonomous AI agents actually reliable in the real world. That means building for failure, designing for observability, and shipping with conviction — not waiting for a perfect spec that will never arrive. * Build the OS for AI Agents — Contribute to a safe, scalable platform that lets us iterate on autonomous agent capabilities faster than anyone else. You are building the infrastructure that makes AI actually work in production. * Ship Resilient Systems — Design and own systems that hold up under failures, retry storms, and resource starvation — with full observability baked in. Reliability is a baseline, not an aspiration. * Take Products from 0 → 1 → Scale — Scope something from scratch, make the early architectural calls, and stay responsible for it as it grows. We build with conviction and we see things through. * Move Fast, Ship Often — Iterate in small increments. Multiple deploys a day. Comfort with ambiguity is not optional — it is the job. The mission moves faster than the roadmap. 💡 WHAT YOU’LL BRING * Substantial tenure building production software at a fast-growing company — fintech, AI, consumer tech, or any environment where pace and stakes were both high * Proven experience owning complex, high-stakes systems end to end — not handing off at merge, but staying accountable through observability, iteration, and scale * Deep fluency in Go (Golang) and comfort operating across a modern backend stack (PostgreSQL, Temporal, GCP, Kubernetes) * A product instinct that goes beyond technical elegance — you think from the customer backwards and bring that into every architectural decision * Senior, Staff, Principal or Distinguished level in practice — someone who has operated with real scope and real accountability * Genuine excitement for autonomous AI as a platform shift, not a trend — you want to build the infrastructure that makes agents genuinely reliable * Strong opinions, loosely held — conviction without ego, and always willing to be wrong in pursuit of the right answer WHY JOIN GRADIENT LABS? This is a unique chance to be part of a team working with cutting-edge technology to reshape how businesses will operate in the future. Over the next 10 years, every company will need to embrace AI-powered operations to stay competitive, and this role puts you right in the middle of that transformation. You’ll tackle challenging and new problems, work with some of the most exciting brands across different industries, and be surrounded by a passionate, smart team that’s driven to build something groundbreaking.