Fullstack Developer

Sactown Asset Labs; United States; Remote; USD 120,000 - 160,000; Full time

Job summary

Sactown Asset Labs seeks a versatile Full Stack Developer to build production web, backend, and cross-platform mobile apps. You will convert AI experiments into production-ready features integrated into enterprise workflows, spanning React web apps, Python APIs, and mobile platforms with offline support.

You will ship end-to-end features, bridging AI capabilities with real data, while collaborating with product, data, and backend teams.

Qualifications

• 3–4 years of professional software development across web, backend and mobile.
• Strong experience with React and Python alongside C#/.NET.
• Experience in vibe-coding to rapidly architect and orchestrate code with LLMs.
• Experience building AI tools and frameworks (Gemini API, LangChain, etc.).

Responsibilities

• Develop Web frontends using React/TypeScript and backends with Python (FastAPI).
• Develop mobile apps using C#/.NET (Xamarin/MAUI) with device features.
• Bridge AI/LLMs into workflows and connect frontend, backend, data streams.
• Manage data systems with SQLite, PostgreSQL, and vector stores.
• Maintain and debug across web, mobile, and backend platforms.
• Collaborate with product, backend, and data teams to deliver features.

Skills

React

Python

C# / .NET

TypeScript

REST APIs

SQL

AI tools

Vibe-coding

Xamarin/MAUI

Tools

FastAPI

pgvector

SQLite

PostgreSQL

Xamarin/MAUI

Job description

We are looking for a versatile Full Stack Developer to build and maintain production web, backend, and cross-platform mobile applications. A core responsibility of this role is taking proof-of-concepts (POCs), prototypes, and AI experiments and converting them into fully functional, production-ready features integrated into real enterprise workflows.

You will work across frontend, backend, and mobile environmentscombining React web applications, Python backend APIs, AI-powered capabilities, and cross-platform mobile apps that support offline usage and mapping. This is a hands-on engineering role focused on shipping real, reliable features end-to-end.

Why This Role Matters

You will directly bridge the gap between experimental AI prototypes, enterprise web platforms, and critical mobile field apps. Your work ensures that data flows seamlessly and systems function reliablyeven in offline environments. You aren't just maintaining code; you are shaping how our users interact with AI and real-time data every single day.

What You Will Work On

• Full Stack Web: Web applications and services using React and Python.
• Cross-Platform Mobile: Android and IOS applications using C# / .NET (Xamarin/MAUI).
• AI Integration: Production-ready features utilizing AI/LLM models and vector search.
• Offline & Real-Time Sync: Mobile workflows that support reliable offline storage and data synchronization with backend systems.
• Mapping & GIS: Location-based features and field data workflows.
• Prototype to Production: Converting experimental POCs into robust, scalable systems used by real users.

Role & responsibilities

• Develop Web & APIs: Build frontend features using React/TypeScript and backend services using Python (FastAPI).
• Develop Mobile Apps: Build and maintain mobile applications using C# / .NET (Xamarin / MAUI) supporting device features (notifications, camera, barcode scanning).
• Bridge AI & Systems: Integrate AI/LLM APIs into application workflows and connect frontend, backend, and data/AI streams.
• Manage Data Systems: Work with structured and unstructured data, building search, retrieval, and offline storage logic (SQLite, PostgreSQL, pgvector).
• Maintain & Debug: Investigate, debug, and resolve production issues across web, backend, iOS, and Android platforms.
• Collaborate: Partner closely with product, backend, and data teams to deliver end-to-end user features.

Requirements

• 3-4 years of professional software development experience across web, backend, and mobile environments.
• Strong experience with React and Python alongside C# and .NET.
• Experience in "vibe-coding"the ability to rapidly architect, prompt, and orchestrate functional application code from high-level concepts using LLMs.
• Experience building with AI tools and developer frameworks (e.g., Google Gemini API, Agno, LangChain, or similar agentic/LLM libraries).
• Experience building cross-platform mobile applications(Xamarin, MAUI, or similar).
• Strong experience building and integrating REST APIs and handling modern authentication flows.
• Solid SQL and database fundamentals (relational design, query optimization).
• Strong debugging and problem-solving skills across both web and mobile environments.

Preferred Qualifications

• Experience integrating AI/LLM APIs, vector databases, or retrieval-augmented generation (RAG) systems in production.
• Experience working with offline-first architectures or enterprise-grade mobile applications.
• Experience with mapping, GIS-based applications, or location SDKs.
• Experience publishing apps to the Apple App Store or Google Play Store.
• Exposure to cloud deployment pipelines (CI/CD).

Tech Stack

• Frontend: React, TypeScript
• Backend & AI: Python (FastAPI), PostgreSQL, Vector Databases (pgvector or similar), AI Developer SDKs(Google Gemini API, Agno, etc.), REST APIs
• Mobile: C# / .NET, Xamarin / MAUI, SQLite, Push Notifications, Mapping/GIS SDKs