Senior Full Stack Software Developer

Apex Multifamily Builders•Austin, TX

20h•$100,000 - $130,000

About The Position

ApexOS360 is building an enterprise-grade operating platform for construction companies — project management, financials, field operations, document control, and real-time reporting in one system. Think Procore-level capability, built by people with 27+ years actually running construction projects across Texas and Colorado. The Role Own the entire product development process from day one. Architect, design, code, test, and deploy a production-grade SaaS platform on an aggressive timeline. You'll work directly with leadership, have full autonomy on technical decisions, and full accountability for results. This is a ground-floor opportunity to be the technical backbone of a product built to scale.

Requirements

5+ years professional software development experience
Proven track record taking a product from concept to live production deployment
Experience with multi-tenant SaaS or enterprise platform architecture
Strong full-stack skills: modern front-end frameworks, server-side languages, relational databases
Deep system design and architecture understanding
Cloud platform experience (AWS/Azure/GCP) including DevOps, CI/CD, and containerization
Strong security fundamentals: OAuth 2.0, JWT, RBAC implementation
Experience with API development, third-party integrations, and data conflict resolution
Ability to work independently and communicate clearly to non-technical leadership
Bias toward action — ship and iterate over endless planning

Nice To Haves

Construction tech, project management platforms, or B2B SaaS experience
Mobile development (React Native, Flutter)
Startup or small-team environment background
Accounting system integrations (QuickBooks, Sage)
Real-time dashboards or BI features
Knowledge of construction workflows and field operations

Responsibilities

Own the full development lifecycle: architecture, design, development, testing, deployment, and iteration
Design and build multi-tenant SaaS architecture with isolated data across multiple organizations
Build modular platform structure (project management, financials, document control, field ops, reporting) that scales independently
Develop data-rich front-end interfaces (React, Vue, or equivalent) including dashboards, Gantt charts, cost code views, and real-time collaboration tools
Build robust back-end systems (Node.js, Python, or similar) with RESTful/GraphQL APIs and automated business logic workflows
Design relational database schemas (PostgreSQL/MySQL) for complex construction data: projects, budgets, cost codes, change orders, contracts, lien waivers, daily logs
Implement role-based access control (RBAC) with multi-level permissions across user types
Build document management with version control, cloud storage (AWS S3), full-text search, and large file handling (100+ MB)
Set up cloud infrastructure (AWS/Azure/GCP): auto-scaling, load balancing, Docker/Kubernetes, CI/CD pipelines
Build third-party integrations (QuickBooks, Sage, DocuSign, scheduling/ERP systems)
Develop mobile functionality via React Native, Flutter, or PWA with offline capability