Senior Engineer (Full Stack / Platform)

Role Overview

About Senior Partner OS

Senior Partner OS (SPOS) is an early-stage legal technology company. We've built a product that is currently a working proof of concept. We're now looking for a highly senior engineer to assess the current system, identify what is reusable, and define the right path to a secure, scalable MVP.

The Role

SPOS is looking for a senior technical builder to help evaluate and shape the next phase of the product's development.

The initial focus of this role is to review the current application, infrastructure, and codebase; identify technical debt, architecture risks, and security gaps; and establish a practical plan for moving the product toward a stable, secure MVP.

This is not a standard feature-development role. The ideal candidate will be comfortable working in an early-stage environment, partnering directly with a non-technical founder, and balancing hands-on engineering with architecture, security, and platform decision-making.

For the right fit, this role may extend beyond the initial assessment phase into hands-on development and longer-term product ownership.

Initial engagement structure:

• Phase 1: 4-week assessment and advisory phase, up to 10 hours/week
• Focus will be on reviewing the current product, assessing the codebase and architecture, and recommending next steps toward MVP
• Engagement may extend into longer-term production / development phase based on findings and mutual fit

Timing:

This is an immediate project need. Candidates should be prepared to interview and begin work quickly if selected.

Initial Priorities

• Review and assess the current proof-of-concept application, infrastructure, and codebase
• Identify what is reusable versus what needs refactoring, redesign, or rebuilding
• Assess technical debt, scalability risks, and architecture gaps
• Evaluate security risks, especially around document handling, tenant isolation, and access controls
• Create a clear technical roadmap for bringing the platform to a secure MVP
• Advise the founder on priorities, tradeoffs, and the most practical path forward

Responsibilities

• Review and assess the current proof-of-concept application, infrastructure, and codebase
• Identify technical debt, architecture risks, and areas that need refactoring or redesign
• Create a practical roadmap to bring the platform to a stable, secure MVP
• Harden the existing React / Node.js application for commercial use
• Improve backend architecture, scalability, and maintainability
• Design and implement secure authentication and service-to-service communication patterns across Google Cloud environments
• Maintain and strengthen a zero-trust architecture with strict dual-GCP project boundaries
• Implement and enforce strong multi-tenant data isolation and Firestore RBAC
• Help ensure the platform is built with future SOC 2 readiness in mind
• Support or refine document-hosting, extraction, and RAG-based workflows in a secure SaaS environment
• Implement or refine hybrid, usage-based billing flows using the Stripe Billing API
• Communicate clearly with the founder around risks, priorities, tradeoffs, and roadmap decisions
• Potentially remain involved longer term as the platform evolves beyond MVP

Current Environment

• Frontend: React 19
• Backend: Node.js / Express 5
• Cloud: Google Cloud Run
• Architecture: Dual-GCP project boundary / zero-trust model
• Database / Access Control: Firestore with strict RBAC and tenant isolation
• Billing: Stripe Billing API
• Development Context: Existing product was built rapidly with support from AI coding agents and now needs senior engineering oversight, architectural review, and production hardening

Requirements

• 5+ years of software engineering experience, with strong depth across full-stack development and cloud/platform architecture
• Experience assessing and stabilizing early-stage or fragile products
• Experience taking products from proof of concept to secure, usable MVP
• Strong experience with React, Node.js, Express, and Google Cloud
• Hands-on experience with Google Cloud Run and modern cloud-native deployment patterns
• Experience with Workload Identity Federation or similar keyless authentication models in GCP
• Strong understanding of multi-tenant SaaS architecture and access control design
• Experience implementing secure RBAC patterns in Firestore or similar NoSQL systems
• Experience working with document-heavy platforms, secure hosting workflows, or RAG-based systems
• Strong judgment around system design, technical debt, and when to keep, refactor, or rebuild
• Ability to work directly with a non-technical founder and explain technical decisions in plain English
• Experience in regulated or security-sensitive environments such as fintech, healthtech, legaltech, or adjacent industries is strongly preferred
• Experience building with future SOC 2 compliance requirements in mind is a major plus
• Experience with Stripe billing, metering, or usage-based pricing models is a plus

What Success Looks Like

• You quickly assess the current platform and identify the main technical and security risks
• You establish a clear, credible plan for what should be kept, improved, or rebuilt
• You help stabilize the foundation of the product and reduce risk in the current architecture
• You make technical decisions that support secure early user adoption, future scale, and compliance readiness
• You become a trusted technical thought partner to the founder