Senior SDE - Conversations

High Level is an AI‑powered business operating system that gives agencies, entrepreneurs and SMBs the infrastructure to build, automate and scale. Today, High Level supports SMBs across 150+ countries, fueling community‑driven growth rooted in real customer outcomes. To date, businesses operating on High Level have generated over $7 billion in ecosystem value, demonstrating the impact of shared infrastructure  centralizing conversations, automation and intelligence into one system, we help businesses move faster, reduce complexity and execute efficiently.

Behind the platform, High Level 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. Learn more about us on our You Tube Channel or Blog Posts

With over 2,000 team members across 10+ countries, High Level 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.

Every month, High Level 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.

The systems that run millions of businesses.

Every month, 2.6 billion messages flow through our platform. Our automation engine enrolls 3.1 billion contacts and executes 21.5 billion workflow actions in the same window — with API traffic peaking at 28,000+ requests per second
. Booking appointments, closing deals, answering customers. If these systems lag, businesses lose leads. If they go down, people lose income.

We're hiring backend engineers who treat that as a design constraint, not a fun fact.

This isn't a role where you'll implement someone else's spec. You'll be handed problems that don't have a known answer yet — a datastore buckling under index growth, a queue that needs to absorb 10x burst traffic without dropping a message, a state machine with millions of concurrent executions.
You’ll figure it out. And you’ll own it.

The Conversations organization powers multi-channel communication across SMS, Email, Whats App, 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.

• 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 No
  
  SQL 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

• 4+ years of backend engineering experience, with…