We're looking for a Backend Engineer to help build the core of how Quartz works — the systems that aggregate user data, power Charlie (our AI advisor), and make personalised wealth advice possible at scale.

You'll write Kotlin day-to-day, work across greenfield services and existing systems, and make the kind of early engineering decisions that compound for years. Expect to partner closely with the Head of Engineering on architecture, and with product and ML on how the backend shapes what users experience.

This role is for someone who excels at first principle thinking, is comfortable owning systems end-to-end, and moves with the urgency of a startup while holding the rigour a financial platform demands. If you're looking to do meaningful work and you're not driven by a nine to five mentality, you might be just who we're looking for.

Responsibilities

• Designing and building the APIs and services that power Quartz's mobile and web apps
• Building the data infrastructure that aggregates user accounts and feeds Charlie, our AI advisor
• Owning features end-to-end — from API design through to production rollout and observability
• Partnering with ML and product to translate advisory logic into reliable, testable backend behaviour
• Setting the bar on code quality, testing, and engineering rigour alongside the Head of Engineering

Requirements

• Fluency with Kotlin or Java
• 5+ years of experience in backend development
• To be a quick learner with an ambitious attitude and results-driven personality
• Experience in a start-up or scale-up (at least have started something as a side project!)
• Fluency in English