About Blitzy

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.

The 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.

What Success Looks Like

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

Areas of Ownership

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

Core Technologies & Required Experience

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

Backend

Python (primary language)
Backend frameworks and microservices architectures
RPC-based services (REST, gRPC)
Node.js and JavaScript (supporting languages)

Cloud & Infrastructure

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

Databases & Data Systems

Strong expertise across both SQL and NoSQL databases

SQL: PostgreSQL, MySQL, or similar relational databases
NoSQL: MongoDB, Cassandra, DynamoDB, or similar

Graph databases (Neo4j) for modeling and searching complex relationships
Vector databases / embeddings infrastructure for semantic search and retrieval

AI / LLM Tooling

Experience building and operating LLM-powered systems in production
Designing and implementing LLM validation loops (evaluation, feedback, regression testing, and failure analysis)
LangSmith (or equivalent tooling) for tracing, evaluation, and debugging
Familiarity with specific models or vendors (e.g., OpenAI, Anthropic) is a plus

Frontend & Full-Stack Competency

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

Enterprise Systems

Core understanding of how large-scale enterprise systems are designed, integrated, deployed, and operated
Experience working within — or modernizing — complex, long-lived production environments

Ways to Stand Out

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

Compensation

Total compensation: $300,000 - $500,000

This includes a mix of competitive base salary and equity, tailored to demonstrated Principal-level experience, scope of ownership, and production impact.

You'll Get…

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
The opportunity to re-shape an entire industry and create a platform that changes the future of software creation
A beautiful office environment with adjacent offices shared by other startups — an energizing community
Unlimited snacks, fizzy water, coffee, espresso, and whatever else you need to perform at your best

Our Culture

Who we are: Led by two pioneering co-founders we are one of the fastest growing companies in the U.S., creating our own category of enterprise autonomous software development. We automate thousands of hours of software development for our customers, which includes strong representation within the Fortune 500.

How we work:

We move Blitzy Fast: Time is both our company's and our clients' most precious asset. We move quickly and decisively to innovate internally and deliver exceptional software externally.

Championship Mindset: We operate like a professional sports team. We win as a team by holding ourselves and each other to high standards, collaborating in-person, and remaining focused on the mission.

Principal Software Engineer