Staff Backend Engineer - Phone Billing

About HighLevel:HighLevel is an AI-powered business operating system that gives agencies, entrepreneurs and SMBs the infrastructure to build, automate and scale. Today, HighLevel supports SMBs across 150+ countries, fueling community-driven growth rooted in real customer outcomes. To date, businesses operating on HighLevel have generated over $7 billion in ecosystem value, demonstrating the impact of shared infrastructure at scale. By centralizing conversations, automation and intelligence into one system, we help businesses move faster, reduce complexity and execute efficiently. Behind the platform, HighLevel powers more than 4 billion API hits and 2.5 billion message events daily. With 250 terabytes of distributed data, 250+ microservices and over 1 million domain names supported, our architecture is built for performance, resilience and long-term scalability. Our people With over 2,000 team members across 10+ countries, HighLevel operates as a global, remote-first organization built for speed and ownership. We value initiative, clarity and execution, creating space for ambitious people to build systems that support millions of businesses worldwide. Here, innovation thrives, ideas are celebrated and people come first, no matter where they call home. Our impact Every month, HighLevel enables more than 1.5 billion messages, 200 million leads and 20 million conversations for the more than 1 million businesses we support. Behind those numbers are real people building independence, expanding opportunity and creating measurable impact. We’re proud to be a part of that. Learn more about us on our YouTube Channel or Blog Posts About the Team Even a simple configuration error can lead to significant unintended usage. At HighLevel, we aim to build robust systems that protect our customers and the platform from accidental surges and intentional abuse alike. This team creates the intelligent safeguards that ensure our automation remains safe and reliable for everyone. We are looking for a Staff Engineer to architect the future of Trust, Controls & Safety. You will lead the technical direction of a real-time platform that secures critical workflows across HighLevel—including Signups, SaaS checkouts, User management, and global communication usage. This system processes 160M+ events and $4M+ in transactions daily, serving as the essential foundation for platform integrity. The challenge is to build a highly available, low-latency control plane that balances strict enforcement with a seamless user experience. By integrating synchronous metering with asynchronous signal correlation, you will help us stay ahead of evolving fraud vectors while ensuring that legitimate business activities, from new user signups to complex SaaS billing cycles, proceed without friction. As a Staff Engineer, you'll set the technical direction, own the hardest problems on the platform, mentor engineers across squads, and partner closely with EMs, PMs, Finance, Risk, Support and the channel teams. Getting this right means customers stop getting bills they didn't intend, and abuse stops being a cost the honest majority carries. Responsibilities: Own the end-to-end technical health of Phone Billing — proactively identify architectural bottlenecks, correctness and reliability risks, and technical debt; define and drive the roadmap to improve billing accuracy, reconciliation, scalability, observability, and cost efficiency as the platform scales to 10x its current volume. Drive 1–2 high-impact initiatives end-to-end — take ownership from problem definition and technical discovery through architecture, implementation, rollout, and measurement, ensuring the initiatives deliver measurable improvements to Phone Billing in areas such as accuracy, reliability, scalability, or cost efficiency. Architect for massive scale : Own the high-level architecture and scaling decisions for core Phone platform components, including CPaaS abstractions, provider adapters, and shared messaging/voice APIs that support billions of monthly events. Own Phone Billing end to end : usage metering, rating, reserve/commit lifecycle, idempotency, reconciliation, and audit trails for the Phone channels - with zero tolerance for double-charging or lost usage Lead the evolution of Revenue Growth into a configuration-driven, rules-based platform that adapts to new regulatory and carrier requirements without invasive engineering change Work hands-on with technologies like NestJS, Firestore, MongoDB, PostgreSQL, Redis, Queuing Systems, Data Warehousing Systems and Service Mesh-based microservices Drive high-concurrency innovation : Lead the design and execution of cross-cutting initiatives to improve reliability, latency, and throughput across time-sensitive APIs and workflows serving millions of businesses. Drive observability and resilience by evolving our monitoring, alerting (Prometheus/Grafana), and incident response strategies - including the financial invariants that must be alerted on, not just the technical ones Leverage LLMs and AI tools to write, refactor, test, and debug code efficiently - while implementing guardrails to reduce hallucination and boost reliability Partner with product, infra, security, finance and legal teams to ensure data integrity, access control, and compliance across phone services Develop EM I leaders and senior engineers, build leadership pipeline, succession planning and raise the hiring bar Participate in design reviews, deep dives, and on-call rotations to support a high-bar culture of accountability and operational excellence Requirements: 8+ years of backend engineering experience with 2+ years of Staff role , with a proven track record of designing fault-tolerant systems that operate at a scale of billions of hits or events. Deep expertise in distributed systems, event-driven architectures, and asynchronous job processing Demonstrated experience building systems where correctness is non-negotiable - metering, ledgers, billing, payments, or comparable transactional domains - with a working grasp of idempotency, exactly-once semantics, and reconciliation Proven experience optimizing availability, performance, and reliability in real-world systems under load Strong experience with relational and NoSQL data models (especially with complex transactional data) Experience designing policy- or rules-driven systems that evolve with external requirements rather than hard-coding them Familiarity with monitoring, SLOs, and root-cause analysis in production environments Familiarity with hallucination mitigation strategies (e.g., code constraints, test scaffolding, embeddings, context injection) Excellent communication and cross-functional collaboration skills, including with Finance, Legal and external partners A pragmatic, hands-on leader who balances long-term vision with iterative execution Preferred Skills: Experience with usage-based billing or metering engines in a high-volume product, specifically managing millions of transactional events per hour. Exposure to telecom trust and compliance regimes - 10DLC, toll-free verification, TCPA/TSR, DLT, carrier filtering or number portability Experience building provider-agnostic integration layers across multiple third-party vendors Experience working with AI Tools, Communication APIs (Twilio, Plivo etc) Contributions to open-source tools, internal platforms, or engineering blogs