Principle Software Engineer

Be our CTO's technical partner: Own many domains, deliver work across entire platform, debate roadmap and technical approaches. This is a leadership role without management responsibility.

Real ownership + hard problems + proven team = rare career opportunity.

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What We're Building

Nesso is an AI-powered platform for therapists running private practices.

We combine practice management tools (scheduling, billing, documentation, communication) with AI-driven business insights that help therapists grow as business owners.

📍 Stage: pre-launch, building V1.

Why This Is Interesting

Proven founders who know this space:

• Fletcher Dennison (CEO) and Will Morales (CPO) were the first employees at SimplePractice (the current market leader, IPO in 2021)
• Spent 10+ years building software used by 200,000+ therapists and millions of clients
• Self-funded = accountable to customers, not investors
• Ukrainian CTO building a European engineering team

Technical partnership, not just senior IC:

• CTO's right hand, driving toward V1
• Earn ownership of many technical domains
• Autonomous decision-making
• Critical input in roadmap prioritization, technical, and architectural approaches
• Must thrive in debate culture (decisions challenged to find best solutions)

Hard technical problems you'll solve:

• Building AI therapists can trust with business & clinical judgment
• Designing a HIPAA-compliant architecture from the ground up
• Proactive intelligence that feels like a smart assistant
• Structured, secure clinical data pipeline
• Personalization engine at scale (100K+ therapists, 1M+ clients)
• Secure, responsive architecture across platforms

Unique breadth and leadership, not possible at larger companies:

• No technical challenge is out of bounds. From custom UI interactions → financial reporting → AI pipelines → security architecture → data modeling
• Learn and grow by shipping products across the entire platform

The Tech Stack

Frontend

• React 19, TypeScript 5.5
• TanStack Query v5, Zustand
• Tailwind CSS, shadcn/ui components
• Zod validation, React Hook Form

Infrastructure & AWS

• Node.js 24.x LTS
• SST (Serverless Stack)
• AWS Cognito, Aurora Serverless (PostgreSQL), DynamoDB, S3, Lambda, API Gateway
• Turborepo monorepo with pnpm

Architecture

• Clean Architecture (domain → application → infrastructure layers)
• DDD
• Feature-based code organization
• CQRS pattern for queries/mutations

What We're Looking For

Must have:

• 7+ years of experience in software engineering
• Led architecture decisions — designed systems from scratch or driven major refactors
• Deep TypeScript expertise (strict mode, generics, type-safe patterns across frontend and backend)
• Deep React experience (hooks, performance optimization, state management)
• Node.js backend development (API design, Lambda handlers, async patterns)
• Clean Architecture, DDD, and CQRS
• AWS services (Lambda, API Gateway, Cognito, Aurora/DynamoDB, S3)
• PostgreSQL (schema design, migrations, query optimization)
• Monorepo experience (dependency graphs, build orchestration, shared packages)

Nice to have:

• Serverless-first architecture (SST, CDK, or similar IaC)
• TanStack ecosystem (Router, Query)
• Zod or similar runtime validation at system boundaries
• Real-time systems (WebSockets)
• Scaling serverless workloads
• HIPAA or regulated industry experience
• Payment system integration (Stripe)

Mindset:

• Ownership mentality — you build things end-to-end, problem-solve, and are adaptable
• Intellectually honest — you want decisions challenged to get to the best one
• Breadth-seeking (not narrow specialization)
• Thrive in ambiguity and startup environments

Not for you if:

• Need hierarchy/approval processes
• See debate as conflict
• Want narrow specialization
• Want to manage people now

What We Offer

💰 Compensation:

• Negotiable based on experience
• B2B contract

🕐 Work:

• Fully remote
• Full-time (40+ hours/week)
• Flexible hours

🚀 Growth:

• Merit-based — do great work, take on more ownership, grow your comp and title
• Flexible path (IC or future management)

🌱 Environment:

• Small, focused, senior team
• Minimal meetings, maximum trust
• No investor pressure or bureaucracy

Hiring process

Recruiter screen (30 min) → Technical interview with CTO (2.5+ hrs) → Team fit interview with Head of Design and co-founders (60 min)