Senior Backend Engineer (AI + Identity Systems) at Sport & Reha-Zentrum GmbH Dr. Unkrig

, , Argentina -

Full Time

Start Date

Immediate

Expiry Date

15 Mar, 26

Salary

0.0

Posted On

15 Dec, 25

Experience

5 year(s) or above

Remote Job

Yes

Telecommute

Yes

Sponsor Visa

Skills

Python, FastAPI, OAuth, JWT, SQL, PostgreSQL, SQLAlchemy, REST API, Next.js, React, TypeScript, Database Modeling, CI/CD, Docker, Cloud Run, Testing

Industry

Description

Chrysalis AE — Building Ethical Identity Infrastructure for the Human Internet We’re building the trust layer for AI-native systems: the infrastructure that lets technology adapt to people without exploiting, storing, or surveilling them. Our work sits at the intersection of privacy, consent, and adaptive intelligence, and every part of our architecture is designed to protect the person first. You’ll join early, work closely with our founder, engineering, and product, and help build models that define what ethical, user-owned identity looks and feels like in practice. We’re looking for a Senior Backend Engineer who can own backend services and APIs for our AI-native identity platform, and who is comfortable working full-stack when needed. You’ll be working in an early, fast-moving environment — meaning you’ll help shape architecture, implement features with a high degree of autonomy, and collaborate directly with founders, design, and product. Our stack includes Next.js, React, TypeScript, FastAPI, SQLAlchemy, PostgreSQL, Docker, GCP Cloud Run, and GitHub Actions. We need someone senior enough to take a lightly defined feature and design + implement the full slice— frontend, backend, database, deployment, and testing — with little technical guidance. Reports to: Founder & CEO, Chrysalis AE Responsibilities Backend Feature Ownership Architect and implement backend services and APIs using FastAPI and PostgreSQL Design and enforce authentication, authorization, and consent boundaries (OAuth/JWT) Build SDK-friendly APIs for partner and platform integration Own database models, migrations, and performance tuning Integrate backend services with frontend flows as needed (React / Next.js) Core Engineering Responsibilities Improve overall architecture — component design, API boundaries, service modularity. Write high-quality, maintainable code and tests (pytest, Jest). Own database modeling: designing schemas, writing secure queries, ensuring performance. Manage asynchronous jobs using Google Cloud Tasks where applicable. Work within a containerized environment: Docker Compose locally, Cloud Run in production. Support CI/CD pipelines and help improve deploy reliability (GitHub Actions). Participate in code reviews and raise the engineering bar for the team. Help define best practices for a modern full-stack application. Autonomy + Leadership Identify missing requirements and clarify product decisions without waiting for direction. Break down ambiguous features into actionable milestones. Make pragmatic tradeoffs balancing speed, quality, and long-term maintainability. Collaborate directly with founders and designers; propose technical and UX improvements. Must Have 5+ years of professional experience building full-stack web applications. Python (FastAPI preferred; Flask/Django acceptable) Authentication & authorization (OAuth/OIDC/JWT) Building SDKs Experience building backend services used by multiple clients or integrations SQL and relational data modeling (PostgreSQL strong preference) SQLAlchemy or similar ORM REST API design Next.js (App Router, API integration, SSR/ISR understanding) Comfort working full-stack when needed (React / TypeScript) Ability to take vague product requirements and turn them into production-ready features with little guidance. Comfort working in fast-moving environments, shipping quickly, and iterating with founders and designers. Excellent communication and autonomy while collaborating in a remote-first team. Strong English speaking skills Strong Plus Firebase Auth (used in our frontend) GCP Cloud Run, Cloud SQL, Cloud Tasks MCP Alembic migrations Testing frameworks (pytest, Jest) Shadcn/UI or Radix UI Async Python (asyncpg, async SQLAlchemy) Experience in early-stage startup environments or on 0→1 projects. Comfort working heavily with LLM tools (Claude Code, Cursor, Copilot) for speed and iteration. Why Join This is an early, ground-floor role with the opportunity to help shape the foundational infrastructure for adaptive AI. Work directly with the Founder on a project positioned as the next layer of AI infrastructure. If you thrive on solving hard problems and building what doesn’t yet exist, this is that chance. Details US-based company Remote-first, flexible Full-time contractor position Equity + compensation negotiable

Responsibilities

The Senior Backend Engineer will own backend services and APIs for the AI-native identity platform, architecting and implementing solutions with a focus on ethical identity. They will also improve overall architecture, manage database models, and support CI/CD pipelines.