SDE III - Whatsapp Voice
About us
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
Our Blog Has a New Home :We’ve consolidated our blog experience into one place so you can find the latest HighLevel updates, strategies, and resources faster .
About the Role
As a Senior Software Engineer, with deep expertise in Java/Golang/Node.js, MongoDB, and distributed systems, along with a strong focus on platform stability, scalability, and long-term technical excellence. You’ll join our LC Phone Voice System, which provides capability for voice calling, IVR, SIP and much more.
You’ll be contributing in shaping the experience of our platform. You’ll solve complex challenges across frontend / backend architecture, performance, micro-frontends, and distributed backend systems. You’ll also work on resolving critical voice service issues, such as the carrier-level call blocking and SIP 603 errors reported by clients like Forever Freight Broker. You’ll contribute to overall growth and stability of the platform, collaborate closely with PMs and ensure exceptional user experiences at scale.
Responsibilities
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Own and contribute to architecture and development across products, driving technical excellence in both frontend and backend systems.
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Develop and optimize backend API services with test-driven development including advanced caching and messaging for reliability and scalability.
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Deliver high-quality frontend experiences using modern frameworks, with strong fundamentals in component-based architectures and state management.
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Integrate and support observability, logging, and monitoring to ensure platform reliability and rapid incident response.
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Ensure top-tier application security and compliance, applying best practices across frontend, backend, and API layers (authentication, authorization, rate-limiting, OWASP).
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Leverage LLMs and AI tools to write, refactor, test, and debug code efficiently, implementing guardrails for reliability.
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Participate in design reviews, deep dives, and on-call rotations to support a culture of accountability and operational excellence.
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4+ years of hands-on software engineering experience building and scaling robust backend systems and high-performance frontend applications.
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Strong backend engineering and distributed system design skills, with hands-on experience in API development, data modeling, and systems architecture using Golang/Java/Node.js (NestJS preferred), TypeScript, PostgreSQL, MongoDB, and Redis.
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Expertise in backend performance optimization, caching strategies, and event-driven architectures (e.g., Redis, Kafka, Pub/Sub).
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Familiar with modern frontend frameworks (React, Vue, Angular), advanced UI engineering patterns, and CSS libraries like Bootstrap or Tailwind CSS.
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Advanced experience with complex state management libraries (e.g., Redux, Vuex, MobX) and architectural design of large-scale application state.
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Proven track record of optimizing frontend performance and web vitals at scale, including experience with server-side rendering (SSR), edge, or hybrid rendering architectures.
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Familiarity with frontend and backend observability - including monitoring, tracing, error tracking, and performance profiling in production (e.g., Grafana, Prometheus, Sentry, PostHog).
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Strong understanding of security best practices across the full stack—including authentication, authorization, access control, secure data flow, and privacy compliance.
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Excellent communication and cross-functional collaboration skills, able to drive complex initiatives, lead technical discussions, and mentor junior engineers.
EEO Statement
As published by lever
Resume/CV, Full name, Pronouns, Email, Phone, Current location, Current company, LinkedIn URL, Twitter URL, GitHub URL, Portfolio URL, Other website
- What is your current annual salary? written answer
- What is your expected annual salary? written answer
- Walk me through the tech stack you work with day-to-day.What languages, frameworks, and databases do you use — and for what purpose? How long have you worked with each, and where would you rate your depth (familiar / proficient / expert)? Have you migrated from one stack to another? What drove that decision? written answer · optional
- Describe the most complex backend or frontend problem you've solved — walk me through it. What was the business context and why did it matter? written answer · optional
- Tell me about the largest scale system you've worked on — give me the actual numbers. What was the peak load — RPS, DAUs, data volume, message throughput? What was your role — did you design it, inherit it, or scale it up? Where did the system start breaking as load grew, and what were the early warning signs? How did the architecture evolve — what did v1 look like vs. where it is now? What was the most surprising thing that failed at scale that you didn't anticipate? written answer · optional
- Walk me through the most impactful performance optimisation you've shipped. How did you first identify the problem — was it user-reported, alerting, or proactive profiling? What tools did you use to diagnose — flamegraphs, query plans, distributed traces? What did you try that didn't work, and why did it fail? What was the measurable before/after — latency p50/p99, throughput, infra cost? written answer · optional
- What services or components do you personally own — describe your domain. What does each service do, what are its SLAs, and who are its consumers? How do your services communicate — REST, gRPC, event-driven, message queues? Why that choice? written answer · optional