Principal Backend Engineer

Our Culture

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.

About 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.

Responsibilities

• Own mission-critical production systems end-to-end, ensuring correctness, scalability, performance, reliability, and operational excellence.

• Design, build, and ship high-impact backend systems and features that improve product reliability, performance, and customer value.

• Architect scalable services and cloud infrastructure using technologies such as Python, REST, gRPC, Kubernetes, and Terraform.

• Identify and resolve complex technical bottlenecks that limit engineering quality, system performance, or organizational velocity.

• Build and operate LLM-powered systems and validation loops that evaluate correctness, consistency, durability, and production performance.

• Design and evolve data architectures incorporating relational, NoSQL, graph, and vector databases to support complex enterprise applications and semantic retrieval.

• Modernize and improve complex enterprise systems while balancing reliability, maintainability, scalability, and delivery speed.

• Set and uphold engineering quality standards through hands-on technical leadership, sound technical judgment, and ownership of long-term technical decisions.

Qualifications

• 12+ years of direct experience with Python as a primary programming language, backend frameworks, and microservices architectures.

• Expertise in REST and gRPC, with proficiency in Node.js and JavaScript.

• Proficiency in AWS, along with experience using at least one additional cloud platform such as GCP or Azure.

• Advanced knowledge of Kubernetes and Terraform in production environments.

• Experience operating highly available production systems, including monitoring, scalability, reliability, performance optimization, and operational tooling.

• Strong knowledge of SQL and NoSQL databases, including PostgreSQL, MySQL, MongoDB, Cassandra, or DynamoDB.

• Familiarity with graph databases such as Neo4j and vector databases or embedding infrastructure for semantic search and retrieval.

• Hands-on experience building and operating LLM-powered systems in production, including evaluation, validation, regression testing, tracing, and failure analysis.

• Working knowledge of LangSmith or comparable LLM observability and evaluation tools; familiarity with OpenAI, Anthropic, or similar model providers is a plus.

• Ability to contribute across the full stack, with a strong understanding of frontend architecture and the ability to debug, design, and ship across frontend, backend, infrastructure, and AI systems.

• Understanding of large-scale enterprise software systems, including architecture, integration, deployment, modernization, and long-term maintainability.

• Proven track record of operating at Staff+, Principal Engineer, or comparable scope, independently driving complex technical initiatives and delivering high-impact outcomes with minimal supervision.