Principal Engineer; Backend​/Platform

Blitzy is a Cambridge, MA based rapidly scaling Generative AI start-up.

The Blitzy platform enables thousands of AI Agents to ‘think’ and cooperate for hours to generate high-quality code at scale for enterprises. The platform specializes in working with large-scale enterprise codebases and executing large-scale changes. The platform builds everything AI can deliver in a precise manner — around 80% of any roadmap or large-scale feature addition — supplemented with a human engineering guide to complete the remaining 20% needed for production.

We deliver 3x–5x engineering velocity improvements to our enterprise customers. With over 27 patents and counting, Blitzy is actively hiring senior technologists in Cambridge, MA who have a passion for building AI that leverages “System 2 Thinking” to solve problems  company is rapidly growing.

Compensation:

Expected total compensation is in the range of $300K–$500K , with a mix of cash and equity that reflects the scope, ownership, and impact of the role.

Final packages are tailored to demonstrated Principal-level experience and production ownership.

Location:

One Kendall Square, Cambridge MA 02139 (In-person role)

We are hiring a Principal Engineer to take full, hands‑on ownership of Blitzy's most critical production‑grade systems and to deliver high‑leverage features that materially improve customer outcomes and engineering velocity.

This is the most senior individual contributor role at the company today.

This is not a Senior‑plus role, an architecture‑only role, or a promotion‑track role. We are looking for someone who has already operated at Principal / Staff+ scope in a highly technical environment and expects to spend their time writing, reviewing, and shipping production code.

This role is 100% hands‑on. Leverage comes from system ownership, execution quality, and durable technical decisions — not people management or process.

• You independently own mission‑critical production systems end‑to‑end
• You ship high‑leverage features that materially improve reliability, performance, and customer value
• You raise the technical bar through working code and outcomes, not reviews alone
• You identify and resolve the hardest technical bottlenecks limiting quality or velocity
• You make technical decisions with long‑term impact and stand behind them in production
• You are a self‑directed learner requiring minimal supervision
• You are dedicated to getting things done right without making technical compromises
• You demonstrate strong technical expertise across the full stack : frontend, backend, infrastructure, and AI systems
• You materially increase the effectiveness of the engineering organization through example and judgment

• End‑to‑end ownership of production‑grade backend systems used by enterprise customers
• Correctness, scalability, performance, and operational reliability in real environments
• Delivery and stewardship of high‑impact features, not just incremental improvements
• Building and improving Blitzy using Blitzy, holding the platform to real‑world standards
• Designing, operating, and evolving LLM validation loops to ensure correctness, consistency, and durability in production
• Setting engineering quality and durability expectations across teams without direct reports

This role demands strong, hands‑on experience across the full technology stack. You should have deep expertise in most of the following:

• Python (primary language)
• Backend frameworks and microservices architectures
• RPC‑based services (REST, gRPC)
• Expertise across at least two of AWS, GCP, and Azure, with GCP mandatory
• Expert‑level Kubernetes experience for container orchestration in production environments
• Terraform for infrastructure as code
• Production systems: monitoring, reliability, scalability, and operational tooling

• Strong expertise across both SQL and No
  
  SQL databases
• SQL:
  Postgre
  
  SQL, MySQL, or similar relational databases
• Graph databases (Neo4j) for modeling and searching complex relationships
• Vector databases / embeddings infrastructure for semantic search and retrieval

• Experience building and…