Senior Software Development Engineer ( Labs)

About the Role:

We're looking for a Software Development Engineer III (Full Stack) to join our Labs team. Labs is the platform that powers how HighLevel ships new features to production — controlling staged rollouts, feature flags, and experimentation across the platform, and closing the loop with in-product customer feedback.

Today, every new capability shipped across HighLevel's platform passes through Labs' feature-flag and rollout infrastructure, spanning 100K+ agencies and the 2M+ businesses they serve. The systems we build directly shape how safely and quickly the rest of the engineering org can ship — enabling gradual rollouts, targeted enablement at the company and location level, and fast, safe rollback when something goes wrong.

The team builds and scales core capabilities across feature flag management, staged feature rollout, and customer feedback collection. These systems let product and engineering teams control exactly who gets a feature and when, monitor adoption and health in real time, and gather structured feedback directly from agencies and locations to inform what ships next.

As an SDE-3, you'll play a key role in building and evolving these systems across the frontend and backend, while contributing to technical architecture and engineering decisions. You'll work on challenges involving high-throughput flag evaluation, scalable APIs and services, distributed systems, and data architecture — with a strong focus on reliability, low latency, and correctness, since every other team's shipping velocity depends on this platform working correctly.

You'll collaborate closely with Product Managers, Designers, and other Engineers across the org to take features from requirements and technical planning through implementation and production, while contributing to technical decisions and continuously improving the systems you own.

• Own and contribute to the architecture, design, and development of key product areas across Feature Flags, Staged Rollouts, and Customer Feedback within the Labs platform.
• Design and build scalable backend services, APIs, and integrations, working across internal microservices and third-party platforms such as Statsig, with a strong focus on reliability, security, and performance.
• Build performant and scalable frontend experiences for feature flag management, rollout configuration, and feedback collection workflows using modern frontend frameworks and component-driven architecture with strong state management practices.
• Drive technical decisions, identify risks and trade-offs, and independently own complex features from technical design through production.
• Leverage AI-first development practices and AI-assisted development tools to improve development, testing, debugging, and refactoring while maintaining strong quality and security standards.
• Design data models and build efficient queries and caching strategies across data stores such as MongoDB and Redis, optimized for low-latency flag evaluation at scale.
• Participate across the full Software Development Life Cycle (SDLC), from requirement analysis and technical design to implementation, deployment, monitoring, and production support.
• Write clean, efficient, secure, and testable code with appropriate unit and integration test coverage.
• Build and maintain effective observability through logs, metrics, monitoring, and tracing to improve system reliability and enable faster production issue resolution — critical given that other engineering teams depend on Labs to ship safely.
• Participate in code reviews, technical design discussions, incident resolution, and operational support, including on-call responsibilities where applicable.
• Collaborate closely with Product Managers, Designers, and other Engineering teams to translate business requirements into scalable technical solutions.
• Follow engineering best practices around security, scalability, maintainability, testing, documentation, and production readiness.

• 4+ years of hands-on software engineering experience building and scaling robust backend systems and high-performance frontend applications.
• Strong backend engineering skills with hands-on experience in Node.js, TypeScript, API development, data modeling, and system design. Experience with NestJS is preferred.
• Strong understanding of RESTful API design, microservices architecture, distributed systems, and cross-service communication.
• Hands-on experience working with data stores such as MongoDB and Redis, with a strong understanding of data modeling, query design, and performance optimization.
• Experience working with event-driven architectures and messaging systems such as GCP Pub/Sub, Kafka, RabbitMQ, or similar technologies.
• Exposure to AI/LLM application development, such as integrating LLM APIs, prompt/context design, or building AI-assisted product workflows.
• Good frontend development experience with modern frameworks such as Vue.js, React, or Angular, with Vue.js preferred, along with a good understanding of component-driven architecture and modern CSS frameworks such as Tailwind CSS or Bootstrap.
• Experience with frontend state management patterns and libraries such as Vuex/Pinia, Redux, MobX, or similar solutions.
• Good understanding of production observability and debugging, including logging, monitoring, tracing, error tracking, and performance profiling using tools such as Grafana, Prometheus, Sentry, or similar platforms.
• Experience with modern SDLC practices, Agile development methodologies, Git workflows, automated testing, and CI/CD pipelines.
• Familiarity with specialized data platforms such as ClickHouse and Elasticsearch, and an understanding of when to use document databases, analytical/columnar databases, and search engines.
• Familiarity with modern developer productivity tools, including hands-on experience with AI-assisted development tools such as Cursor, Claude Code, GitHub Copilot, or similar tools.
• Strong problem-solving and debugging skills, with the ability to investigate issues across frontend, backend, databases, integrations, and distributed services.
• Excellent communication and cross-functional collaboration skills, with the ability to drive technical discussions, make sound engineering trade-offs, and mentor other engineers.
• Strong ownership mindset with the ability to independently drive complex engineering problems and deliver high-quality solutions.

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