Senior Full Stack Developer (Equity Only | Remote | Flutter + FastAPI)

JR United Kingdom; City Of London; Remote; GBP 70,000 - 100,000; Part time

Job summary

A leading company is seeking a Senior Full Stack Developer to join their innovative team focused on building a unique community-driven platform. This equity-only role offers flexible hours and the opportunity to influence product direction while working remotely. Ideal candidates will have extensive experience in Flutter and Python, thriving in startup environments.

Benefits

Equity in a high-potential, early-stage company

Flexible hours and remote-first culture

Influence over product and technical direction

Qualifications

• 10+ years of experience, with a minimum of 5 years in Flutter, Python, AWS.
• Experience in building clean, scalable, production-ready apps.
• Bonus: experience with AI, community platforms, or content moderation.

Responsibilities

• Leading frontend and backend development of the Nanu platform.
• Building scalable features using Flutter and FastAPI.
• Collaborating closely with the founder and lead developers.

Skills

Flutter

Python

AWS

AI

Tools

PostgreSQL

Redis

SQLAlchemy

Pydantic

Pytest

Job description

Job Title: Senior Full Stack Developer (Equity Only | Remote | Flutter + FastAPI)

Company: Unknown Systems

Location: Remote (London-based preferred)

Job Type: Equity-Only | Part-Time or Flexible Hours

About the Role

Unknown Systems is building Nanu, a groundbreaking platform that investigates unexplained phenomena through community-submitted experiences and AI-powered tools.

We're looking for a Senior Full Stack Developer to join us at a pivotal moment. This is an equity-only role perfect for someone excited by early-stage building, who wants to help launch something truly unique.

You’ll Be Responsible For:

• Leading frontend and backend development of the Nanu platform
• Building scalable features using Flutter and FastAPI
• Collaborating closely with our founder and lead developers
• Contributing to architecture, infrastructure, and product evolution
• Helping shape the future of a global community-driven product

Our Tech Stack:

• Frontend: Flutter (iOS, Android, Web)
• Backend: FastAPI, Python
• Database: PostgreSQL
• Auth: AWS Cognito
• Infra: Redis, Alembic, SQLAlchemy, Pydantic, Pytest
• AI: OpenAI API integrations
• Feed: Multi-factor ranking system for personalised content

You’re a Great Fit If You:

• Have 10+ years of experience (min 5+ with Flutter, Python, AWS)
• Love building clean, scalable, production-ready apps
• Thrive in startup environments and take ownership
• Are curious, open-minded, and mission-driven
• Bonus: experience with AI, community platforms, or content moderation

What We Offer:

• Equity in a high-potential, early-stage company
• Flexible hours and remote-first culture
• Influence over product and technical direction
• A chance to build something that truly matters