Senior Full-Stack Engineer

Acorns, the financial wellness app, is building a new Community product team from scratch. This is a small, senior group with a single mandate: Get people addicted to saving by unlocking network effects inside Acorns. This team understands how to create engagement loops, virality, and habit formation. We want people who’ve mastered those mechanics and are ready to use them for something that improves people’s lives.

As a Senior Full-Stack Engineer on this team, you’ll build the systems and features that power Acorns’ organic growth engine. Social graphs, engagement loops, referral mechanics, real-time interactions, sharing flows, the infrastructure that makes a product spread. You’ll own your features end-to-end: API design, server logic, implementation, instrumentation, and iteration. You’ll work directly with the CEO, a Senior Product Manager and a Senior Product Designer.

This is end-to-end ownership from early concept through shipped product on features where what you build will reach millions of people who are often investing for the first time.

The Impact You’ll Make

• Build the mechanics that make a product spread including referral systems, social sharing flows, engagement loops, and real-time features that drive Acorns’ organic growth
• Own features end-to-end from data model to shipped customer experience, across mobile and web, with full accountability for quality and performance in production
• Deliver features end-to-end across iOS, Android, Web, and backend services, moving fluidly between platforms depending on what each initiative requires, and leveraging AI-assisted development tools to accelerate work in less-familiar codebases
• Instrument your work properly: define the events, build the visibility, and use data to iterate fast
• Take full ownership of the technical bar and architecture, while upholding engineering standards, where your decisions have outsized impact and every voice counts
• Partner directly with the CEO, a Senior PM, and a Senior Designer in a tight, high-trust team that moves fast and ships things people actually use

Some Things You’ve Likely Done in the Past

• Built social or engagement systems at scale with feeds, referral flows, notification infrastructure, social graphs, or real-time interactions at a gaming or consumer social company
• Owned a feature end-to-end across the full stack: you designed the data model, wrote the API, shipped the client, and monitored it in production
• Shipped production features across more than one client platform (iOS, Android, or Web) - you have depth in at least one and have demonstrated you can build in the others with ramp-up time and modern tooling
• Instrumented a growth or engagement feature with analytics events and used the data to drive meaningful iteration
• Worked in a fast-moving, low-process environment where you drove your own work without waiting to be told what to build next
• Used AI-assisted development tools (Claude, Copilot, or similar code-generation tools) as genuine accelerators - you see them as force multipliers, and have a clear point of view on how to use them well
• Written production code or had exposure in two or more of the following technologies: Swift, Kotlin, React Native, Typescript, Dart, or Python that served millions of users
• Built something - a side project, an open source tool, a game mechanic - because you wanted to, not because someone asked you to