Senior Full-Stack Engineer – React / Python (IoT Platform Rebuild)

About the Project

An industrial IoT platform serving retail and industrial clients is undergoing a full greenfield rebuild. The existing single-tenant system has outgrown its architecture, and the approved path forward is a modern, modular monolith built from scratch. You'll be the primary engineer on this rebuild, working directly with a hands-on product manager to deliver a platform that covers real-time device monitoring, energy and fluid-level tracking, helpdesk and work-order management, and client invoicing. The engagement is full-time, fully remote, and planned for 6+ months.

Tech Stack

Backend: Python
Frontend: React
API Layer: OpenAPI (API-first design)
Architecture: Modular monolith

Responsibilities

- Architect and build the full-stack platform from scratch, following an agreed modular monolith structure with a clean separation of concerns
- Design and implement an OpenAPI-first API layer, ensuring contracts are defined before implementation and remain the source of truth throughout
- Build frontend interfaces in React for real-time data visualisation — device status, energy readings, fluid levels, alerts, and reports
- Develop backend modules for device and installation management, helpdesk and work-order workflows, and invoicing
- Work within an agentic co-programming workflow, where AI tooling plays an active role in development, guided by a structured AOP-based system of coding guidelines and constraints
- Maintain high standards of code quality and scalability throughout — this codebase is expected to evolve well beyond the initial build
- Collaborate closely with the product manager, who owns the architecture vision and coordinates delivery

What We're Looking For

- 5+ years of full-stack development experience with React and Python as your primary stack
- Demonstrated experience designing and building modular monolith or similarly structured architectures from the ground up — not just maintaining existing systems
- Solid command of OpenAPI and API-first design practices
- Comfortable working in an AI-assisted development workflow — you've used AI tooling as a genuine co-programming tool, not just autocomplete
- Ability to operate with a high degree of autonomy as the sole technical contributor, while staying aligned with a non-technical or semi-technical PM
- Strong instincts around code quality, structure, and long-term scalability — you write code that can be built on, not just shipped
- Familiar with AOP principles or structured coding constraint systems, and able to apply and work within such guidelines in practice

Nice to Have

- Experience with IoT-adjacent platforms or real-time data streams — device telemetry, sensor data, event-driven patterns, or similar
- Exposure to multi-tenant architecture considerations, even if the chosen approach for this project is still being defined
- Background in industrial, energy, or field-service software domains

Being a part of 3asoft means having

- High level of flexibility and freedom

- P2P relationship with worldwide customers

- Competitive compensation paid in USD

- Fully remote working