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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Principal Software Engineer - **Company:** BLITZY INC. - **Location:** Cambridge, MA, United States - **Experience:** Expert - **Salary:** $300,000.0 - **Contract:** Permanent contract - **Skills:** JavaScript (Programming Language), Artificial Intelligence, Amazon Web Services, Microsoft Azure, Cloud Computing, Databases, Data Systems, Relational Databases, Software Debugging, Amazon DynamoDB, Graph Database, Python (Programming Language), PostgreSQL, MongoDB, MySQL, Neo4j, Node.Js, NoSQL, Regression Testing, Search Technologies, SQL Databases, Google Cloud, Enterprise Software Applications, Large Language Models, Backend, Kubernetes, Cassandra, Production Code, Front End Software Development, Terraform, Grpc, Service Stack, Microservices - **Published:** September 4, 2026 - **Apply:** https://startup.jobs/principal-software-engineer-blitzy-8023900 ## About the Role 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 1. Graph databases (Neo4j) for modeling and searching complex relationships 2. 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 ## Description 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 ## Related Videos - [MySQL Protocol Features You Should Be Aware Of](https://www.wearedevelopers.com/videos/100267-mysql-protocol-features-you-should-be-aware-of) - [Putting the Graph In GraphQL With The Neo4j GraphQL Library](https://www.wearedevelopers.com/videos/257-putting-the-graph-in-graphql-with-the-neo4j-graphql-library) - [Exploring the Power of gRPC-Gateway for Writing RESTful Services](https://www.wearedevelopers.com/videos/2072-exploring-the-power-of-grpc-gateway-for-writing-restful-services) - [You are not an AI developer](https://www.wearedevelopers.com/videos/1148-you-are-not-an-ai-developer) - [Coding for Good: Achieving social change with an app](https://www.wearedevelopers.com/videos/1645-coding-for-good-achieving-social-change-with-an-app) - [Cyber Sleuth: Finding Hidden Connections in Cyber Data](https://www.wearedevelopers.com/videos/893-cyber-sleuth-finding-hidden-connections-in-cyber-data) ## Related Articles - [What Are Large Language Models?](https://www.wearedevelopers.com/magazine/304-what-are-large-language-models) - [Why Upskilling And Reskilling is Important For Developers](https://www.wearedevelopers.com/magazine/428-why-upskilling-and-reskilling-is-important-for-developers) - [How We Built a Worry-Free System That Runs for 10+ Years – And What We’d Do Again](https://www.wearedevelopers.com/magazine/751-how-we-built-a-worry-free-system-that-runs-for-10-years-and-what-we-d-do-again) - [Graph and AI Trends 2026: Why Is AI Running but Not Yet Delivering?](https://www.wearedevelopers.com/magazine/680-graph-and-ai-trends-2026-why-is-ai-running-but-not-yet-delivering) - [The Prompt Engineer ✍️](https://www.wearedevelopers.com/magazine/216-the-prompt-engineer) - [Highest Paying Tech Companies for Developers](https://www.wearedevelopers.com/magazine/220-highest-paying-tech-companies-for-developers)