Principal Software Engineer & Team Lead

AddSource is building an infrastructure management platform from scratch and seeks a Principal Software Engineer who actively writes code while leading technical efforts. This role involves owning the architecture and design of core platform services, mentoring engineers, and driving the delivery of critical capabilities, all while ensuring high standards of reliability and performance.

Responsibilities:

• Own architecture and system design for core platform services, ensuring they meet reliability, security, compliance, and performance requirements
• Lead end-to-end delivery of critical platform capabilities, from technical discovery and design through implementation, rollout, and ongoing improvements
• Drive technical excellence in the codebase, setting standards for code quality, testing, performance, and observability, and ensuring they are adopted across the team
• Mentor and grow senior engineers, providing clear technical direction, constructive feedback, and opportunities for ownership
• Collaborate with product, platform, and security leaders to translate business needs into technical roadmaps, and make thoughtful trade-offs between speed, safety, and maintainability
• Continuously improve platform operability, including deployment strategies, telemetry and alerting, incident response practices, and post-incident learning
• Identify and mitigate technical risks, proactively addressing scaling, reliability, and security concerns before they impact customers

Requirements:

• 10+ years of software engineering experience, with 4+ years in senior/staff/principal roles shipping production systems
• Expert-level TypeScript proficiency—you can build complex, type-safe applications and reason deeply about the type system
• Expert-level Next.js experience building production full-stack applications with SSR, API routes, and modern React patterns
• Strong Go experience for backend services, CLIs, and systems-level tooling
• Deep expertise in API design—RESTful APIs, versioning, error handling, and building interfaces developers love to use
• Experience building control planes, reconciliation loops, or state machines for infrastructure automation
• Strong understanding of distributed systems principles and how to design for eventual consistency and failure
• Hands-on experience with cloud platforms (AWS/GCP/Azure) and infrastructure-as-code tools
• Proven ability to own and deliver complex systems end-to-end, from design through production operation
• Track record of mentoring engineers, setting technical direction, and raising the bar for code quality
• Experience building developer tools, SDKs, or CLIs that other engineers depend on
• Strong opinions on testing, observability, and building systems that are easy to debug and operate
• Contributions to open-source infrastructure or developer tooling projects
• Experience building multi-tenant platforms with tenant isolation and resource management
• Deep PostgreSQL experience—schema design, query optimization, and handling high-write workloads
• Background with event-driven architectures and messaging systems (Kafka, NATS, etc.)
• Experience designing secure systems with RBAC, secrets management, and compliance requirements
• Performance engineering skills—profiling and optimizing Go and TypeScript applications
• Prior experience at infrastructure or developer tools companies