Full Stack Engineer, Contacts

Ready to make a serious impact? Millions of people already rely on Calendly, and we’re still in the midst of exciting product growth — it’s a fantastic time to join us. Everything you’ll work on here will accelerate your career to the next level. If you want to learn, grow, and do the best work of your life alongside the best people you’ve ever worked with, then we hope you’ll consider allowing Calendly to be a part of your professional journey.

Calendly’s Contacts team is building a system that turns contacts data into a rich, reliable system of record and unlocks new engagement workflows for our customers. We own the core contact data model, ingestion and enrichment pipelines, and the experiences that make it easy for users to act on their relationships across Calendly.

We’re taking a 0 - 1 product to its next phase of maturity, scale, and innovation. That means evolving our architecture, hardening our platform, and rapidly iterating on new AI-powered workflows that help solopreneurs and teams turn meetings into meaningful relationships.

You’ll report to an Engineering Director in Contacts and partner closely with other team leaders in driving our Contacts technical strategy.

We’re looking for a Staff Engineer who can:

• Own critical parts of our Contacts stack end-to-end, from technical design to rollout and ongoing reliability.
• Guide the evolution from early-stage architecture to a scalable, well-instrumented, multi-tenant system that other teams can safely build on.
• Lead big, cross-cutting “0–1 to 1–100” initiatives in partnership with Product, Design, and other Engineering teams
• Raise the technical bar for the team through mentoring, eng leadership, and high-quality execution.

On a typical day,
you will:

• Design and evolve services and data models for contacts and relationships that can support new workflows and downstream consumers.
• Drive decisions around our APIs, eventing, and data flows to keep Contacts a reliable system of record.
• Own complex, high-impact projects (e.g., new ingestion pipelines, enrichment features, or contact-centric workflows) from technical discovery through launch and iterative improvement.
• Break down ambiguous problem spaces into clear milestones and incremental, ship-as-you-go plans.
• Provide technical leadership across squads and work streams, helping teams make good tradeoffs on performance, reliability, and complexity.
• Mentor senior and mid-level engineers, review design docs and PRs, and codify best practices in testing, observability, and production readiness.
• Collaborate with PMs and designers to translate customer problems into pragmatic solutions, especially for solopreneurs and small teams adopting CRM for the first time.
• Help define MVP scopes, instrumentation, and learning loops so we can move fast without compromising trust or data quality.
• Define and improve SLOs, error budgets, and operational playbooks for Contacts services.
• Participate in on-call, guide incident response, and drive durable corrective actions that reduce repeat issues.

• Deep experience (typically 8–10+ years) building and operating backend or full-stack systems in B2B SaaS, with meaningful time at Staff level or higher.
• Proven track record leading 0–1 products and scaling them through maturity including making and revisiting foundational architectural decisions.
• Strong background in distributed systems, data modeling, and API design; experience with high-traffic, high-availability platforms is a plus.
• Fluency in at least one of our primary stacks (e.g., Go, Type Script/Node, React) and comfort moving across the stack where needed.
• Experience with modern cloud infrastructure (GCP or similar), container orchestration (Kubernetes), and relational databases like Postgre
  
  SQL; familiarity with eventing, CDC, or search platforms is a plus.
• Strong testing discipline (unit, integration, and end-to-end), observability (logging, metrics, tracing), and performance tuning.
• Experience with CRMs, marketing/sales tooling, or other data-centric systems where data quality and trust matter.
• Comfort working in product-led…