Senior Backend Developer - Python (SDE II / III)

Role Description :

We are building a next-gen AI-native CAD software platform that combines scalable cloud-native services with advanced 3D modelling workflows. As a Senior Backend Engineer, you will design, develop, and optimize backend systems that power multi-user collaboration, secure data handling, and seamless integration with CAD Core and AI services.

This role focuses on Python and FastAPI, cloud-native architecture, and the reliability, data security, and AI safety of an AI-native CAD platform.

Responsibilities :

- Architect and build scalable backend services in Python (FastAPI), ensuring performance with large datasets and multi-user workloads.

- Own reliability, data security, and AI safety - encryption, secure APIs, secrets management, SOC 2 (Type II), and guardrails on AI inputs and outputs.

- Implement multi-tenant access control (RBAC/ABAC) to secure projects and enforce fine-grained permissions.

- Design service-to-service communication between backend services, CAD Core APIs, AI Engine, and Kafka.

- Build the AI backend - RAG pipelines and the AI sandbox that ingests clients' legacy CAD data and emits code and designs, with engineers in the loop.

- Integrate with external engineering software and systems of record, keeping data in sync.

- Manage file storage and processing pipelines for CAD/3D files (DWG, IFC, BREP), including large binary data handling.

- Build real-time collaboration features (concurrency handling, versioning, conflict resolution).

- Develop and maintain cloud-native, Infrastructure-as-Code deployments on AWS (ECS, S3, RDS, Kafka) using Terraform.

- Create CI/CD pipelines for backend microservices using Git, Docker, and Bitbucket Pipelines.

- Proactively identify scalability bottlenecks and optimize database queries, file processing, and distributed systems.

- Collaborate with frontend teams (PyQt desktop, Unreal Engine visualization, React web) to deliver seamless CAD workflows.

Tech Stack & Qualifications :

- Bachelor's degree in computer science/engineering or equivalent professional experience.

- 5+ years backend development experience for SDE III (3+ for SDE II), with strong expertise in Python (FastAPI).

- Proven experience in scalable system design with microservices and async processing.

- Strong knowledge of Postgres and familiarity with NoSQL databases (MongoDB, Redis, DynamoDB, etc.).

- Hands-on experience with cloud deployments (AWS), Infrastructure-as-Code (Terraform), Docker, and CI/CD.

- Solid understanding of security, encryption, multi-tenant ACLs, and compliance (SOC 2); familiarity with AI safety / LLM guardrails.

- Past experience with AI/ML systems - knowledge graphs, RAG, AI harnesses and safety, and model fine-tuning.

- Familiarity with OpenAPI and code-generation tools for typed API clients and SDKs.

- Working knowledge of networking and the TCP/IP stack.

- Experience with message queues (Kafka, RabbitMQ, or equivalent).

Benefits :

- Opportunity for professional growth and advancement within the company.

- Competitive salary and benefits package.

- Dynamic and inclusive work environment with opportunities to collaborate with talented professionals.

- Exposure to cutting-edge technologies and projects in the software industry.