Senior Backend Developer
First seen by Alion on Sep 21, 2026.
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.
Skills
Python, FastAPI, PostgreSQL, AWS, AI Integration, Kafka, Microservices Architecture, NoSQL, Cloud