Software Engineer

Looking for a job that fits your life, anywhere in the world? 🤔 Ever fancied a role where work molds around your life, no matter where around the globe you are? Welcome to Keystone AI ! We're all about making work fit into your world, wherever that may be. About us: At Keystone AI , we're not your average company. Sure, we enable global expansion without the risk for over 1,500+ customers in nearly 190 countries, but what really makes us tick is giving you and 900+ Guardians the freedom to work in a way that suits your style, no matter the time zone in 50+ countries. 🌎 Our “ work in any way” approach means you can call your couch your office or a café halfway across the world your boardroom, all while still having room to do school runs and essential errands throughout your working day. 🤩 What we're after: We're building software used by companies around the world to solve complex global payroll, compliance, and workforce management challenges. As we scale, we're transforming our platform into a serverless, event-driven architecture on AWS. This is a core engineering initiative, and you'll play a key role in shaping how our systems evolve. We're hiring multiple engineers across several teams, so depending on your strengths and interests, you could work on areas like: Knowledge Platform Client Account Management Integrations Client analytics Time and Attendance All teams share a common goal: building reliable, scalable systems that power critical business operations for our customers. This is a fully remote role, working with a distributed team. What You'll Do Design and ship agentic systems end-to-end — tool calling, sub-agent orchestration, memory, durable state, and failure recovery Build evaluation frameworks from the ground up — golden datasets, regression harnesses, and systematic approaches to measuring whether your AI systems actually work Own AI features from prototype to production: observable, maintainable, cost-aware Work with product and domain engineers to identify where AI has real leverage — and where it doesn't Contribute to how we build AI across the org: patterns, tooling, and standards that others build on Manage the operational economics of AI systems — latency, token cost, context efficiency — as first-class engineering concerns What Will Give You an Advantage Demonstrated production experience with agentic systems: tool calling, multi-step orchestration, memory management, or RAG pipelines — with evidence (shipped product, open source, or portfolio) You've built evaluation infrastructure, not just run evals — you know how to measure non-deterministic systems systematically Strong backend engineering in TypeScript/Node.js; comfortable with Python for AI tooling and evaluation work Hands-on with AWS serverless (Lambda, EventBridge, S3, API Gateway) You operate with high autonomy — you move from ambiguous problem to shipped system without needing the path laid out for you Experience with reliability patterns: retries, idempotency, observability, failure-mode recovery Infrastructure as Code (CDK, Terraform, or similar) Nice to Have Experience with multi-agent orchestration frameworks (LangGraph, CrewAI, Anthropic SDK) Exposure to LLM safety, guardrails, or responsible AI patterns in production Fine-tuning or RLHF exposure Experience in multi-tenant SaaS platforms Familiarity with modern data stacks (dbt, Athena, data lakes) How We Work Fully remote, async-friendly, and collaborative Small teams with end-to-end ownership Ship often via CI/CD Strong focus on reliability, observability, and real-world impact We actively use AI-assisted development tools (e.g. Cursor, ChatGPT) to speed up workflows and reduce boilerplate​ We are hiring this position across multiple countries; compensation varies by hiring location. For target markets located within the European Union (EU), base salaries start from: Spain: €74,000.00 We are committed to pay transparency and equal pay for equal work at Keystone AI . Compensation decisions are based on objective criteria including skills, experience, scope of responsibility, and market benchmarking, in line with internal salary structures. Our Global Benefits 👨 ‍ 💻 Autonomy and Flexibility (work in any way): Remote first, with the flexibility to include life needs like school runs and gym breaks in your schedule , all while maintaining a high standard of work. 🌴 Generous leave: Enjoy a competitive leave package including paid bonding leaves for new additions to your family 🎁 Make a difference: Get 2 paid charitable days off to contribute to causes you believe in 💰 Corporate bonus/SIP: All Guardians are eligible for our annual bonus scheme or sales incentive plan. ✈ ️ International environment: Grow your network internationally and collaborate across the world. Interact, discover cultures, and tap into local expertise. ⭐ Human centered culture: We emphasize the people factor in everything we do. Our nurturing culture ensures your ideas reach