Senior SDE - Conversations

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:: Design and build Node.js / Go services on critical paths — high throughput, low latency, zero tolerance for data loss Own systems end to end: architecture, design docs, code, tests, rollout, and production health Model and optimize data layers across SQL and NoSQL stores handling high read/write volumes and atomic updates Build queueing, caching, and rate-limiting layers that keep the platform graceful under burst traffic Instrument everything — logs, metrics, traces — so you know your system is healthy before anyone asks Debug production incidents, ship the fix, drive the post-mortem to closure Review code, raise the bar, and pull the engineers around you up with you. Requirements:: 4+ years of backend engineering experience, with deep hands-on work in Node.js and/or Go Queueing experience — you've designed with Pub/Sub, Kafka, RabbitMQ, Cloud Tasks, or similar, and you understand delivery semantics, ordering, and backpressure Complex distributed systems experience — consistency trade-offs, idempotency, fault tolerance, systems that stay correct under partial failure Hands-on with Redis or other in-memory data stores — caching strategies, data structures, and their failure modes Strong with SQL or NoSQL databases — schema design, indexing, and query optimization at high volume You write clear design docs and rigorous test cases as a habit, not on request Champion of AI-assisted engineering — you make agents produce accurate, production-quality code, fast Technical Environment:: Languages : Node.js (TypeScript), Go Storage : MongoDB, Firestore, Redis, ElasticSearch, ClickHouse Infra : GCP — GKE, Pub/Sub, Cloud Tasks CI/CD : GitHub Actions, Docker, Kubernetes On AI: We're past the debate. AI is part of how we build — and we expect you to be better at it than most . That means making agents do real work: producing code that's accurate, tested, and slop-free — fast. You know when to hand a problem to an agent and when to take the wheel. You review AI output with the same rigor as a junior engineer's PR, and you ship at a pace that engineers without this skill can't match. If you're still copy-pasting from a chat window and hoping, this isn't the seat for you. What you're built for: You've solved problems nobody handed you a playbook for — ideally in a 0→1 environment where the system didn't exist until you built it You understand systems in depth — not just the API surface, but what happens under load, at the tail, when the network partitions You write design docs people actually read — clear trade-offs, honest risks, a real recommendation You treat test cases as part of the design , not a chore after the fact When production breaks at 2 AM, your first instinct is curiosity, not panic Bonus Points: Familiarity with our stack: GCP, MongoDB, Firestore, ClickHouse, ElasticSearch You've built or scaled messaging, automation, or event-driven platforms You've taken a system from 0→1, or rebuilt one mid-flight without breaking it