Principal Software Engineer
About The Position
Blitzy is a Cambridge, MA based AI software development platform on a mission to revolutionize the software development life cycle by autonomously building custom software to unlock the next industrial revolution. We're transforming how enterprises build software, turning enterprise requirements into production-ready code with an agentic software development platform that can autonomously execute 80% of the quantum of software development work. We're backed by multiple tier 1 investors, and have proven success as founders of previous start-ups. 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.
Requirements
- Strong, hands-on experience across the full technology stack
- Deep expertise in Python (primary language)
- Experience with backend frameworks and microservices architectures
- Experience with RPC-based services (REST, gRPC)
- Experience with Node.js and JavaScript (supporting languages)
- Expertise across at least two of AWS, GCP, and Azure, with GCP mandatory
- Expert-level Kubernetes experience for container orchestration in production environments
- Experience with Terraform for infrastructure as code
- Experience with production systems: monitoring, reliability, scalability, and operational tooling
- Strong expertise across both SQL and NoSQL databases
- Experience with SQL: PostgreSQL, MySQL, or similar relational databases
- Experience with NoSQL: MongoDB, Cassandra, DynamoDB, or similar
- Experience with Graph databases (Neo4j) for modeling and searching complex relationships
- Experience with Vector databases / embeddings infrastructure for semantic search and retrieval
- Experience building and operating LLM-powered systems in production
- Experience designing and implementing LLM validation loops (evaluation, feedback, regression testing, and failure analysis)
- Experience with LangSmith (or equivalent tooling) for tracing, evaluation, and debugging
- Strong understanding of frontend frameworks and architecture
- Ability to evaluate and contribute to frontend technical decisions
- Demonstrated technical expertise across the full stack — you can debug, design, and ship across frontend, backend, infrastructure, and AI layers
- Core understanding of how large-scale enterprise systems are designed, integrated, deployed, and operated
- Experience working within — or modernizing — complex, long-lived production environments
Nice To Haves
- Prior experience operating at Principal Engineer / Staff+ scope at a highly technical company
- Deep understanding of how enterprise software systems are built and evolved at scale, including tradeoffs around reliability, change management, and long-term maintainability
- Clear ownership of complex systems that you designed, built, and supported in production
- Hands-on ownership of LLM validation loops used to ensure correctness and durability in real environments
- Experience designing systems that combine graph, vector, and traditional data models to support reasoning over complex domains
- Proven ability to deliver outsized impact through the right features, not just more code
- Track record of being a self-learner who requires minimal supervision and gets things done without compromising on quality
- Familiarity with specific LLM models or vendors (e.g., OpenAI, Anthropic)
Responsibilities
- Independently own mission-critical production systems end-to-end
- Ship high-leverage features that materially improve reliability, performance, and customer value
- Raise the technical bar through working code and outcomes, not reviews alone
- Identify and resolve the hardest technical bottlenecks limiting quality or velocity
- Make technical decisions with long-term impact and stand behind them in production
- Be a self-directed learner requiring minimal supervision
- Get things done right without making technical compromises
- Demonstrate strong technical expertise across the full stack: frontend, backend, infrastructure, and AI systems
- 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
- Ensure correctness, scalability, performance, and operational reliability in real environments
- Delivery and stewardship of high-impact features, not just incremental improvements
- Build and improve Blitzy using Blitzy, holding the platform to real-world standards
- Design, operate, and evolve LLM validation loops to ensure correctness, consistency, and durability in production
- Set engineering quality and durability expectations across teams without direct reports
Benefits
- Competitive salary and equity
- Paid medical, dental, and vision insurance for you and your dependents
- 4% 401(k) match
- Flexible vacation days, sick days, and work-from-home days
- Technology (hardware, software, reading materials, etc.) equipment and/or allowance
- Unlimited snacks, fizzy water, coffee, espresso
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What This Job Offers
Job Type
Full-time
Career Level
Principal
Education Level
No Education Listed
