Senior Software Developer, Rust

We’re introducing Rust where correctness, performance, and reliability truly matter. Keystone AI is Growing! Keystone AI is a multi-language platform, and we’re intentional about where we apply Rust. We’re looking for senior engineers to help us bring Rust into the backbone of the system — the parts that must be fast, safe, and correct under real-world scale. This role is for engineers who want agency: people who enjoy identifying the right problems, choosing the right tools, and owning systems end-to-end. You won’t be handed a narrow ticket queue. You’ll help decide what gets built and how it should be built. For this role, you should be located in Canada and able to work within EST/EDT or PDT/PST hours. We are fully remote. Day-to-day Design and build high-correctness Rust services that sit on critical platform paths Introduce Rust into areas where safety, determinism, and performance are essential Own systems from architecture → implementation → rollout → operations Make real decisions around concurrency, async boundaries, data integrity, and failure modes Work across service boundaries in a polyglot environment (Rust alongside other stacks) Collaborate with product, design, and frontend engineers to build systems that are technically sound and product-aware Improve reliability, observability, and system behavior through design, not just patching Mentor other engineers and raise the bar on system quality and ownership What We’re Looking For We care more about judgment and ownership than credentials. You’re likely a strong fit if you: Have built and operated distributed systems in production Have deep hands-on Rust experience (not just experiments or side projects) Understand where Rust shines — and where it doesn’t Are comfortable reasoning about concurrency, async systems, and correctness guarantees Have experience designing APIs and data contracts that evolve safely over time Have worked with relational and/or NoSQL databases at scale Have deployed and operated services in AWS or GCP (We are a GCP Shop though!) Take initiative naturally and are comfortable operating with ambiguity Communicate clearly and make tradeoffs explicit Bonus Points These aren’t hard requirements, but strong indicators: You’ve worked in startup or high-ownership environments You’ve owned systems in production, including on-call responsibility You’re comfortable moving across the stack when needed (backend-first, full-stack aware) You’ve influenced architecture by earning trust, not by mandate You use modern tooling (including AI-assisted workflows) to increase leverage , not outsource thinking (Note: we care about outcome and judgment, not how flashy your tools are.) Why Rust at Keystone AI? Because some parts of the system deserve stronger guarantees. We use Rust where: Bugs are expensive Latency and throughput matter Safety and correctness are non-negotiable You’ll help define where Rust belongs , not just write Rust in isolation. Why Keystone AI (From an Engineer’s Perspective)? Real scale, real customers, real impacts Startup-level ownership with platform-level impact Teams that value thinking, judgment, and responsibility Low ego, high trust, and room to do your best work Why Keystone AI? We're on a mission to simplify the everyday lives of consumers. Post-purchase is a critical phase of the customer journey. That's why we created Keystone AI - a platform focused on driving customer loyalty through seamless post-purchase experiences that allow retailers to retain, engage, and delight customers. If you've ever bought something online, there's a good chance you've used our platform! From the hottest new direct-to-consumer companies to retail’s most renowned brands, Keystone AI works with GameStop, Neiman Marcus, Sonos, Nike, and 1300+ + other brands. With hubs in San Francisco, Atlanta, London, and Bangalore, we've served over 125 million consumers worldwide across 10+ billion interactions, 38 countries, and 55 languages. Pioneering the post-purchase movement means navigating into the unknown. Our team thrives on this sense of adventure while nurturing a mindset of innovation. We're a home for big hearts and we leave our egos at the door. We work hard but we always make time to celebrate professional wins, baby showers, birthday parties, and everything in between. We are an equal-opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. #LI-Remote Please read our Privacy Policy to learn what personal information we collect in connection with your job application, and how we may use and share it.