Principal Full Stack Engineer | $90-$120/hr + Remote | Inc. 5000 Award-Winning, High-Growth Coaching Company

PhillyTech.Co•Miami, FL

1d•$90 - $120•Remote

About The Position

This is a hands-on, player-coach role for a Principal Full Stack Engineer who will lead a small development team while owning complex product and architectural work. The engineer will write and review production code, make pragmatic architecture decisions, guide employees and contractors, and drive delivery in partnership with Product and the existing platform architect. A key requirement is proven experience building proprietary AI capabilities for an AI SaaS product from the ground up. The role involves engineering the AI application layer and production systems, including retrieval and RAG pipelines, embeddings and vector search, persistent memory and member context, stateful workflows, tool use, orchestration, guardrails, and AI-driven personalization. The engineer will assess the production codebase for security, scalability, performance, architecture, data protection, and reliability risks, then prioritize and implement improvements for a safe and stable public launch. Over time, the role will take increasing ownership of the platform’s technical health and architecture, including its stability, security, scalability, reliability, and continued evolution. The position owns features end to end, from data modeling and architecture through implementation, testing, deployment, monitoring, and production support. It works across the full stack with a strong backend focus while contributing hands-on Vue.js frontend development. The engineer will also serve as the internal technical counterpart to outside engineering partners, support technical knowledge transfer from the existing platform engineer, design and execute testing, evolve relational data models and PostgreSQL systems, work with listed platform integrations, and use AI coding agents while maintaining standards for correctness, reliability, security, and maintainability. The role is remote, but candidates must be available for at least 5–6 hours overlapping an 8–5 or 9–6 Mountain time schedule. It is unavailable to candidates in California, New York, New Jersey, or Pennsylvania. This is a contract-to-hire opportunity: the initial contractor period is three months, with the possibility of transitioning to a full-time W-2 role with benefits based on performance. Compensation is USD $90–$120 per hour.

Requirements

8 to 12+ years of software engineering experience.
Strong production experience with Vue.js and deep hands-on experience with relational database design.
Strong experience owning significant portions of a production platform across backend architecture, databases, APIs and integrations, infrastructure, deployment, monitoring, troubleshooting, and production support.
Proven experience developing an AI-native SaaS product or substantial proprietary AI product capability, from initial architecture through production launch and ongoing operation.
Experience assessing production applications for security, scalability, reliability, and performance risks, including identifying vulnerabilities, protecting sensitive customer data, diagnosing bottlenecks, and implementing pragmatic improvements.
Demonstrated technical leadership of small development teams, including hands-on mentorship, architecture reviews, work planning, coordination, and delivery while personally contributing code.
Experience reviewing and validating other engineers’ or external development partners’ work, including architecture, code quality, testing, security, scalability, and production readiness.
Ability to quickly understand and contribute within an existing codebase and technical direction, identify material risks, and make pragmatic improvements rather than defaulting to unnecessary rewrites or redesigns.
Experience owning production readiness, including monitoring, incident troubleshooting, release processes, technical QA, and resolution of critical production issues.
Proven experience using AI coding agents on a production codebase to improve productivity without replacing sound technical judgment.
Highly organized and self-sufficient, able to operate independently and make sound technical decisions in a fast-paced environment.
Enthusiasm for a startup environment and a track record of adapting to changing priorities and taking increasing technical ownership as a company scales.
Must be available for at least 5–6 hours within an 8–5 or 9–6 Mountain time schedule.
Must not be located in California, New York, New Jersey, or Pennsylvania.

Nice To Haves

PostgreSQL experience is preferred.
Experience with Nuxt and Prisma is a plus.

Responsibilities

Lead a small engineering team by setting technical direction within agreed product priorities, mentoring developers, delegating work, conducting code and design reviews, coordinating contractors, removing blockers, and maintaining accountability for quality and delivery.
Design and implement proprietary AI product capabilities, including retrieval and RAG pipelines, embeddings and vector search, persistent memory and member context, stateful workflows, tool use, orchestration, guardrails, and AI-driven personalization.
Assess the production codebase for security vulnerabilities, scalability and performance bottlenecks, architecture risks, data protection concerns, and reliability issues; prioritize and implement pragmatic improvements for a safe, stable public launch.
Take increasing ownership of the platform’s technical health and architecture, including stability, security, scalability, reliability, and continued evolution.
Own features end to end, from data modeling and architecture through implementation, testing, deployment, monitoring, and production support.
Work across the full stack with a strong backend focus and contribute hands-on to Vue.js frontend development and customer experience.
Act as the internal technical counterpart to outside engineering partners by reviewing architecture and code, validating deliverables, and ensuring work meets product, security, scalability, and production requirements.
Partner with the existing platform engineer on knowledge transfer covering architecture, codebase, environments, infrastructure, accounts, deployments, documentation, and operational procedures.
Design, automate, and execute functional, regression, load, and smoke testing.
Design and evolve relational data models, PostgreSQL schemas, queries, indexes, migrations, and Prisma models.
Work across integrations including Stripe Connect, LiveKit, Twilio, Zoom, Anthropic, and pgvector.
Use AI coding agents to accelerate development while maintaining high standards for correctness, reliability, security, and maintainability.