Software Development Engineer III — Payments

About UsHighLevel is an AI powered, all-in-one white-label sales & marketing platform that empowers agencies, entrepreneurs, and businesses to elevate their digital presence and drive growth. We are proud to support a global and growing community of over 2 million businesses, comprised of agencies, consultants, and businesses of all sizes and industries. HighLevel empowers users with all the tools needed to capture, nurture, and close new leads into repeat customers. As of mid 2025, HighLevel processes over 4 billion API hits and handles more than 2.5 billion message events every day. Our platform manages over 470 terabytes of data distributed across five databases, operates with a network of over 250 microservices, and supports over 1 million hostnames.Our PeopleWith over 1,500 team members across 15+ countries, we operate in a global, remote-first environment. We are building more than software; we are building a global community rooted in creativity, collaboration, and impact. We take pride in cultivating a culture where innovation thrives, ideas are celebrated, and people come first, no matter where they call home.Our ImpactAs of mid 2025, our platform powers over 1.5 billion messages, helps generate over 200 million leads, and facilitates over 20 million conversations for the more than 2 million businesses we serve each month. Behind those numbers are real people growing their companies, connecting with customers, and making their mark - and we get to help make that happen.What you'll doOwn services end‑to‑end: Design and ship multi‑tenant services (checkout, payments orchestration, subscriptions, settlement & reconciliation, invoicing, tax hooks).Integrate payments at depth: Add PSPs and local methods (cards/3DS, UPI, wallets, BNPL) with resilient webhooks and strictly idempotent APIs.Model money correctly: Implement an append‑only double‑entry ledger; use event sourcing/CQRS where it meaningfully improves correctness and scale.Raise the quality bar: Ship production‑grade code with contract, integration, property‑based, and performance tests; instrument everything with OpenTelemetry.Run it like you own it: Operate on GKE (GCP) with CI/CD, canaries, autoscaling, SLIs/SLOs, incident response, and on‑call participation.Collaborate & mentor: Partner closely with PM/Design and mentor SDE I/II engineers to multiply team impact.What you'll leadCross‑service designs that connect orchestration ledger reconciliation with clear contracts and failure‑mode analysis.Reliability strategy: Define SLIs/SLOs, capacity models, and multi‑region failover plans; drive DR and chaos drills.Data lifecycle: Establish data retention/archival strategies compliant with regulatory requirements.Engineering excellence: Level‑up design reviews, postmortems, and technical strategy across the Payments & Commerce domain.Minimum Qualifications3–6+ years building backend services, with strong and NestJS experience.Practical expertise with MongoDB and/or Firestore (transactions, indexing), plus cache design with Redis and event‑driven architecture (Kafka, GCP Pub/Sub).Strong grasp of distributed systems fundamentals: idempotency, retries/backoff & jitter, message ordering, de‑dup/outbox for "exactly‑once‑ish" processing, race conditions, concurrency control, and eventual consistency.Hands‑on with Kubernetes and at least one cloud (GCP preferred); familiarity with secrets/KMS and PCI basics.Deep testing discipline: unit, integration, contract, and performance testing.Schema design: Design and plan schemas with a focus on scalability and backward compatibility.Strong problem‑solving and debugging skills.Nice to haveFrontend: Vue 3 + Vite.Data & analytics: BigQuery, Dataflow/Beam, Snowflake.Multi‑region design: Experience with latency budgets and consistency trade‑offs.Observability at scale and hands‑on chaos/DR practice.Prior experience at a fintech, payment processor, or e‑commerce company.What success looks like (first 6–12 months)You own 1–2 services from design production with P99 latency targets met and zero Sev‑1s caused by your changes.Failure retry rates drop by >30% through improved idempotency and retry/backoff policy.Codebases are measurably cleaner (coverage up, linting strict, typed contracts) and you actively mentor 2+ engineers.You define or sharpen SLIs/SLOs, capacity models, a multi‑region failover plan, and data retention/archival standards for your area.The company is an Equal Opportunity Employer. As an employer subject to affirmative action regulations, we invite you to voluntarily provide the following demographic information. This information is used solely for compliance with government record keeping, reporting, and other legal requirements. Providing this information is voluntary and refusal to do so will not affect your application status. This data will be kept separate from your application and will not be used in the hiring decision.