Senior Full-Stack + Mobile Developer

Senior, solo-ownership role responsible for the entire JAPA platform end to end: a .NET/React web portal, a Flutter mobile app (iOS + Android), and the WordPress public website. The candidate owns architecture, code, deployments, monitoring, and production incidents across all three codebases without supervision, and serves as technical lead and mentor for a junior developer.

Tech Stack

Backend

• .NET 10 / C#, ASP.NET Core Web API
• Entity Framework Core + PostgreSQL
• Clean Architecture, MediatR (CQRS), FluentValidation
• ELSA Workflows 3.x
• Redis, Stripe, JWT authentication

Frontend (Web)

• React 19 + TypeScript
• Material UI v7, TanStack React Query
• React Hook Form + Zod

Mobile

• Flutter 3.x + Dart (iOS + Android)
• Riverpod 2.x, Dio, Freezed, json_serializable
• Secure storage, deep linking, file upload

Public Website

• WordPress + WPForms
• Integrations with JAPA Portal APIs

Infrastructure

• PostgreSQL, Redis, DigitalOcean App Platform
• Docker, GitHub, CI/CD pipelines
• Email and notification services, background jobs, * Implement features end-to-end: database to API to web UI to mobile screen
• Write EF Core migrations and coordinate schema changes across all layers
• Develop, maintain, and extend ELSA workflow definitions
• Add Riverpod providers and Dio repositories for new API endpoints
• Run build_runner to regenerate Freezed/JSON code after DTO changes
• Maintain WordPress + WPForms integrations with portal APIs
• Maintain Stripe payment webhook reliability, idempotency, and reconciliation
• Write and maintain tests: xUnit (backend), React testing tools (web), flutter_test (mobile)
• Build and submit mobile releases to App Store and Google Play
• Set up and maintain CI/CD pipelines (GitHub Actions, including self-hosted UAT runner administration)
• Monitor application health, logs, and production performance
• Manage environment configuration, secrets, and infrastructure
• Follow established coding standards without supervision
• Mentor junior developers through pair programming, code review, and structured growth feedback; set the engineering bar for the team
• Operationalize AI tooling across the codebase - coding agents, AI-assisted code review, log/anomaly analysis, and monitoring workflows - so output scales independently of headcount

Ownership

This is a solo ownership role across the portal backend, web frontend, Flutter mobile apps, and WordPress public website. The candidate must treat the platform as their own product: proactively identifying issues, driving quality, and making decisions without waiting to be told. Full ownership is expected, from architecture decisions and code quality to deployments, monitoring, and production incidents. The candidate must be capable of handling all required work independently, end-to-end.

Engagement

• Full-time
• Fully remote; flexible schedule, with some availability during US business hours for meetings and collaboration
• Must sign a Non-Disclosure Agreement (NDA) prior to engagement

• .NET / C# - 5+ years, .NET 8 or later (project currently on .NET 10)
• React + TypeScript - 2+ years
• Flutter + Dart - 2+ years production, shipped to App Store + Google Play
• ELSA Workflows or any workflow engine
• Riverpod 2.x state management
• PostgreSQL + caching + EF Core migrations
• REST API design and consumption
• MediatR / CQRS pattern
• Structured logging (Serilog or similar)
• JWT and role-based access control
• OIDC / SSO IdP integration with third-party apps (e.g. HumHub Community via custom auth module)
• Docker and cloud deployments (DigitalOcean App Platform, GitHub Actions including self-hosted runner administration)
• Git / GitHub workflow
• Proven experience as a technical lead and mentor - running code reviews, setting engineering standards, pair-programming, and growing junior developers
• Excellent English fluency - written and spoken - for daily collaboration, code review, technical documentation, and mentoring
• AI integration - experience integrating AI/LLM-powered features into production applications
• AI-assisted development - expert hands-on use of AI coding agents (Claude Code, Cursor, GitHub Copilot, or equivalent) for feature implementation, code review, debugging, refactoring, log/anomaly analysis, and production monitoring on a codebase of this scale
• Stripe payment integration
• Zoom or similar third-party API integration
• WordPress configuration, WPForms, and plugin maintenance