About Zeffy Zeffy is the fastest-growing nonprofit platform in North America, helping organizations raise funds, run events, and engage donors. About The Role As a Staff Software Engineer at Zeffy, you’ll work on key product features while playing a central role in elevating the engineering team. You’ll bring experience that helps others make better technical decisions, navigate complexity with confidence, and maintain our focus on building simple, high-quality solutions as we grow. Development Principles at Zeffy We always optimize the ratio impact / effort, calling it Zeffy perfectionism. We build the simplest solution first to validate ideas quickly, keeping the codebase clean without solving problems that don’t exist yet. We are organized in 2‑month cycles to prioritize radically, setting targets on efficiency, security, stability, and performance. Trust and ownership: every target is clear and owned by one person with full autonomy, not working alone. Continuous improvement: we regularly review and refine our processes, promoting a culture of learning and growth. Our Stack Frontend: React/Next.js (TypeScript) Backend: Nest.js (TypeScript) Database: PostgreSQL, Algolia CI/CD: GitHub Actions, Cypress Preferred Experience (Qualifications) You have at least 8 years of experience as a developer in SaaS or web‑based products that serve high‑volume and rapidly growing user bases. You’ve shipped complex products at scale, learned from real‑world successes and failures, and developed sharp judgment about what truly matters. You bring seniority through expertise and perspective rather than hierarchy, making clear, pragmatic decisions that balance speed, quality, and long‑term thinking. You value clarity over cleverness, simplicity over complexity, and momentum over perfection. You mentor others with empathy, share your experience generously, and elevate the work of the whole team without adding unnecessary process. What’s in it for you 4 weeks holiday + 1 week during Christmas time Competitive stock option program Health insurance (including dental plan) Online Medicine with Dialogue RRSP (REER) program Allowance for ecological transport (bike, transit) Wellness Budget Team volunteering four times per year Offsite summit once a year with the entire team Offices located in the heart of Plateau Mont‑Royal, with flexible, hybrid work possibility Recruitment Process Call with Recruiter (45 min) Meeting with Hiring Manager (1.5h) Case Study (2h) Cultural interview with leadership (1h) Team lunch & Reference check Job offer #J-18808-Ljbffr