(Senior) Staff Engineer - Backend

About the role

Join bonify, Germany's leading platform for credit scoring and financial management. We are on the mission to revolutionize the FinTech industry and make the credit score and financial data available and transparent for our users. We are seeking a talented Sr. Staff Engineer - Backend to join our dynamic team in Berlin. We are hiring a Staff / Senior Staff Backend Engineer to lead the transformation of our AWS-based backend platform, built primarily with TypeScript Lambda functions. This role goes beyond feature delivery: you will reshape architecture, improve system reliability, and define how backend services evolve over the next phase of growth. You will act as a force multiplier across teams, setting technical direction while staying hands-on where leverage is highest. While this is a backend role, we value engineers with an end-to-end mindset. We expect strong partnership across the stack and departments to deliver high-quality, reliable outcomes. Lead modernization of backend services and platform foundations, improving reliability, clarity, and long-term maintainability Evaluate and evolve architecture choices: runtime, service boundaries, and patterns (serverless, containerized services, microservices) as the platform scales Establish and drive best practices for TypeScript and AWS , including API design, event-driven patterns, error handling, resilience, and operational excellence Reduce complexity and operational risk through simplification, standardization, and stronger engineering defaults Improve observability and reliability (metrics, tracing, structured logging, alerting, runbooks, incident learning) Partner closely with product, design, frontend, and infrastructure to enable faster and safer delivery Help improve cross-stack developer experience (shared contracts, typing, integration patterns, tooling) Occasionally contribute to frontend-adjacent work to unblock teams or improve end-to-end reliability, while remaining primarily backend-focused Drive pragmatic decision-making: refactor vs. rebuild, prioritization, sequencing of change Mentor senior engineers and raise the bar through reviews, coaching, shared patterns, and architectural guidance 8+ years of engineering experience (or equivalent impact) Strong hands-on backend experience in AWS , including Lambda, IAM, API Gateway , and event-driven services Strong TypeScript expertise in backend/service contexts Proven ability to lead system-level transformations in production environments (not just greenfield) Strong understanding of distributed systems , failure modes, and operational trade-offs Ability to think in terms of platform leverage : shared primitives, safer defaults, automation, and developer experience Experience decomposing monoliths or untangling tightly coupled services Experience working with data stores (SQL and/or NoSQL) in distributed systems Practical knowledge of Infrastructure-as-Code (CDK and/or Terraform), CI/CD, and modern cloud tooling Solid security mindset: IAM design, least privilege, secure service patterns, and a healthy respect for compliance requirements Ability to balance technical purity with business constraints Strong written and verbal communication - you can explain trade-offs clearly and influence decisions across teams If you enjoy shaping frontend platforms, improving performance and reliability at scale, and raising the bar across teams - we'd love to talk. As part of the bonify team, you'll have: The opportunity to take ownership from day one The chance to thrive in a dynamic and flexible startup environment. Access to extensive coaching and training programs through our personal development budget 30 vacation days Mental health support platform Subsidies for BVG and UrbanSportsClub 1:1 language classes in both German and English. The Company is committed to the principle that no employee or job applicant shall receive unfavourable treatment on grounds of age, disability, gender reassignment, race, religion or belief, sex, sexual orientation, marriage or civil partnership, pregnancy, and maternity. Please note, to be compliant with AML requirements, due to the specifics of fintech industries additional background checks are required (applicable only at the offer stage). If you're ready to make a meaningful impact in the world of FinTech and embark on an exciting career journey, apply now to join bonify!