Staff Engineer - Distributed Systems

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 Role Summary: We’re hiring a Senior Full Stack Engineer to design, build, and scale the backend systems and frontend interfaces that power the Threads & Composer experience inside HighLevel Conversations. You’ll spend most of your time on backend and API design, data flows, and performance — while still owning the Vue 3 UI layer end-to-end. Your work will touch critical paths that process billions of messages per month, demanding reliability, throughput, and correctness at scale. Team & System Overview: The Conversations organization powers multi-channel communication across SMS, Email, WhatsApp, and DMs — handling over 2B messages each month. The Threads & Composer team owns the inbox and composer surfaces, and the backend services that deliver and store those interactions.You’ll work across Node.js microservices, GCP-based infra (GKE, Pub/Sub, Cloud Tasks), and MongoDB/Firestore storage layers, ensuring every message and UI state stays consistent, fast, and recoverable. Responsibilities:: Own the architecture health of a billion-scale distributed system , its failure modes, capacity limits, consistency guarantees, and the interactions between 50+ deployments that no single team can see Approve critical-path designs. Changes that touch the system's core go through you, not as bureaucracy, but as the person accountable for the whole staying sound. When there's a disagreement, you make your case on merit Hunt gaps proactively , single points of failure, unbounded queues, missing idempotency, thundering herds, quiet data-loss windows, and drive the fixes before they become incidents Build the parts nobody else can. No sprint tickets. You prototype the risky architectural bets yourself, ship the remediation after serious incidents, and pair into the gnarliest cross-team bugs, roughly a quarter to a third of your time in code, all of it on the hardest problems Make resilience a property of the system, not a heroic act , degradation strategies, backpressure, isolation boundaries, capacity models that survive 10%+ month-over-month growth Raise the teams around you. Design reviews that teach, post-mortems that change architecture (not just add alerts), and patterns that 80+ engineers build on Set the standard for how AI-assisted engineering works safely on systems this critical, where a bad merge doesn't cost a demo, it costs real businesses their revenue The terrain: Runtime : Node.js (TypeScript), Go, thousands of pods on GKE Messaging & async : GCP Pub/Sub, Cloud Tasks, Redis Storage : MongoDB, Firestore, ClickHouse, ElasticSearch Scale : 21.5B automation actions/month, 2.6B messages/month, 28.5K req/s peaks, ~226B async events across the org Requirements:: 10+ years of engineering experience with deep, hands-on ownership of large-scale distributed systems , comparable scale strongly preferred: hundreds of services or thousands of instances, billions of daily events You've carried sole accountability for a production system through real failures , not adjacent to it, not advising on it. Owned it Deep command of queueing and async architectures , delivery semantics, ordering, backpressure, idempotency, exactly-once myths and at-least-once realities Strong with multiple storage engines (SQL and NoSQL), you reason about consistency models, indexing at scale, and when each engine is the wrong choice Expert-level depth in Redis or comparable in-memory systems , including their failure modes under memory pressure and network partition Production experience on Kubernetes at scale , resource limits, autoscaling behavior, what actually happens when a node pool dies Exceptional design communication , docs, diagrams, and RCAs that drive decisions across multiple teams Fluent in Node.js and/or Go , enough to prototype your own proposals and ship fixes on the critical path What Success Looks Like: The critical paths of Workflows have named owners, capacity models, and tested failure modes , because you made it so Incident count trends down while traffic grows double-digit percent month over month Your design reviews are the ones engineers want their proposals to survive Your scope has expanded on results , more systems, more surface, more trust What you're built for: You've been injured in production. A lot. You've owned distributed systems at serious scale, through the outages, the migrations, the 3 AM discoveries, and every scar changed how you design You've operated at staff scope, whatever your title said , the engineer everyone routed the hardest systems questions to You think in failure modes by default : when you see a design, you instinctively ask what happens at the tail, under partition, at 10x load You write design docs and RCAs that people reference years later , clear trade-offs, honest risks, real recommendations You can disagree with a team and still make them better , influence through rigor and respect, not title You'd rather prevent ten incidents quietly than be the hero of one loudly Bonus Points: You've made AI agents genuinely productive on complex systems , and know how to keep AI-generated code from becoming AI-generated incidents GCP-native experience: Pub/Sub, Cloud Tasks, GKE, Firestore You've done this job before under another name, "the systems person," principal engineer, architect-who-still-codes Experience taking a 0→1 system to production alongside hardening mature ones