Job Description

We are looking for a senior full-stack developer to help build and scale SMSNinja, a contemporary messaging platform designed for charities and fundraising teams.

SMSNinja combines two-way SMS, AI-assisted reply drafting, and team review workflows to help organisations manage supporter conversations more effectively. We are rebuilding the platform on a modern multi-tenant architecture and need an experienced developer who can help turn a strong foundation into a reliable production product.

This is a hands-on role for someone who is comfortable working across frontend, backend, database design, third-party integrations, and production delivery.

Key Responsibilities
Build new product features across the messaging inbox, admin tools, and settings flows
Improve and extend AI-assisted workflows for drafting and reviewing SMS replies
Develop background job and processing flows for async tasks, retries, and syncing
Integrate and harden webhook-driven systems such as Twilio
Design and ship database migrations to support current functionality safely
Improve reliability, observability, and operational safety across the platform
Support fundraising-related integrations and related product workflows
Help shape the product architecture as the platform grows

Skill & Experience




Strong experience building production web applications with TypeScript and React
Comfortable using AI to increase workflow velocity
Solid experience with Next.js
Confidence working on both frontend product work and backend application logic
Solid experience with relational databases, schema design, and migrations
Experience integrating third-party APIs and webhook-based systems
Ability to debug production issues and ship pragmatic fixes quickly
Comfortable owning work end to end, from implementation through rollout
Advantage if have these skills:
Experience with Supabase
Experience with Twilio or other messaging platforms
Experience with queue or job processing systems
Experience building multi-tenant SaaS products
Experience working with AI-powered product features
Experience in fundraising, nonprofit tech, CRM, or supporter engagement tools
You’re likely a strong fit if you:
enjoy building real products, not just prototypes
can move between UI, APIs, data modeling, and infrastructure concerns
are pragmatic, fast, and technically rigorous
are comfortable in an evolving product environment
like taking ownership of meaningful product and platform work

📌 Senior Full Stack Developer Sydney
🏢 Digital Ninjas
📍 Sydney