Staff Backend Engineer

Staff Backend Engineer (Tech Lead) Soter builds an AI platform for EHS and insurance — production agentic system, real customers, ~15 engineers (5 on AI). You'd be on a small team with high ownership. B2B Contract | Start: ASAP | Krakow, Poland (Hybrid — 3 days in the office) About the Role We’re looking for a Staff Backend Engineer with a Tech Lead profile who can own significant parts of our backend platform and drive technical direction across the team. This is a hands-on engineering leadership role — you’ll architect and ship production backend services, lead technical decisions, and raise the engineering bar across the team. We care more about high agency and architectural instincts than years on a CV. If you’re excited about building scalable, cloud-native systems and want real influence on a small, fast team, this is for you. Responsibilities Provide technical architecture and software engineering expert services — design scalable, secure, and high-performance backend systems (Python), including microservices and event-driven architectureAdvise on technical direction across cloud-native solutions (AWS, GCP) and containerisation (Docker, Kubernetes) Identify and recommend solutions to mitigate technical risks related to system performance, scalability, and maintainability Identify and drive refactoring opportunities to improve maintainability, scalability, and long-term system health Lead and mentor engineers — conduct code reviews, define and enforce good engineering practices Own backend services end-to-end — schema, API, deploy, on-call Recommend and implement automated testing frameworks (backend-first) and enforce code quality standards Introduce and maintain monitoring and observability practices to ensure product reliability and performance Own and improve CI/CD pipelines and IaC (Terraform, Ansible) — keep delivery boring and reliable Evaluate security vulnerabilities, provide guidance on security best practices, and ensure developed solutions are secured and threat modelled Collaborate closely with product managers to translate business requirements into technical solutions Must-Have Requirements Proven hands-on experience in backend development — Python is the primary language Strong background in microservices architecture and event-driven systems Extensive experience developing and maintaining cloud-based SaaS applications (AWS and/or GCP) Deep understanding of clean architecture, clean design, and SOLID principles — able to reason about system design clearly, verbally and visually, and apply these to real-world distributed systems Experience with containerisation technologies — Docker and Kubernetes Understands what automated tests are for, knows which type applies where (unit, integration, e2e), and can fit testing strategy into the overall architecture picture Experience with IaC tools (Terraform, Ansible) for managing cloud infrastructure Demonstrated ability to introduce and maintain monitoring and observability practices Solid backend fundamentals: APIs, SQL database design and optimisation Demonstrated ability to work autonomously and own systems end-to-end Demonstrated ability to lead and mentor engineers, conduct code reviews, and promote best practices Strong product focus with the ability to translate business requirements into technical solutions Daily hands-on use of AI development tools (Cursor, Claude Code, Copilot, or similar) — this is a hard requirement; we care about how you use the tool, not which one Fluent English (written and verbal) Self-driven, product-minded, high agency — no hand-holding needed Must-Have (Autonomy) Has owned a non-trivial backend service or platform component end-to-end for 12+ months — design, deployment, on-call, iteration on real user feedback What You'll Work On in Your First 3 Months Audit and improve the architecture of our core backend services — identify and implement quick wins in performance and scalability Take ownership of at least one major backend service end-to-end — schema, API, deploy, on-call Establish or improve observability practices so system health is visible and actionable Conduct code reviews and introduce engineering standards that raise the bar across the team Nice to Have Experience working with multi-agent AI systems Understanding of integration patterns with external systems Node.js backend experience Experience with LLM-powered features or AI-adjacent backend work Hands-on frontend experience with TypeScript, React, and Next.js Why Join Us Join a small team of passionate engineers dedicated to innovation and excellence Work on a product that genuinely improves people's lives and workplace safety Experience a startup culture: fast-paced, close collaboration, real influence on key decisions Short feedback loops — ship fast, learn fast Minimal bureaucracy — focus on what matters: building great software AI-first engineering culture — we embrace and invest in AI-augmented development