Senior Backend Engineer - Consumer Growth

Sword is building AI to heal billions and unlock humanity’s full potential. By pioneering AI Care, Sword has created a fundamentally new approach to healthcare built for medical reasoning, safety, and real-time treatment. As both a clinical-centric frontier AI lab and an applied AI platform, Sword is reimagining how care is delivered at scale, removing traditional barriers like appointments, waiting rooms, and stigma.

Since 2020, Sword has expanded across physical therapy, women’s health, cardiometabolic, and mental health, moving beyond sessions to a fully AI-native, 24/7 care program. More than 700,000 members across three continents have completed over 10 million AI sessions, helping 1,000+ enterprise clients avoid over $1 billion in unnecessary healthcare costs.

AI Proficiency at Sword

AI fluency is a core expectation at Sword. Every candidate is assessed against our three-level framework:

• Explorer (Level 1): Uses AI daily to boost personal productivity
• Builder (Level 2): Creates workflows and tools that elevate the whole team
• Integrator (Level 3): Embeds AI into products and processes at scale

Every hire must demonstrate at least Level 1 proficiency.

Role Overview

As a Senior Backend Engineer in Consumer Growth at Sword, you’ll build the services that help people discover our products, become paying members, experience value, and stay engaged over time. Working closely with Product, Design, Data, Marketing, and mobile engineers, you’ll turn growth opportunities into reliable, measurable product experiences spanning acquisition integrations, onboarding, subscriptions, and retention.

What You'll Be Doing

• Design, build, and operate backend services and APIs supporting the consumer journey across web, Android, and iOS.
• Build subscription and payment capabilities, including checkout integrations, purchase-to-account linking, entitlements, renewals, and subscription lifecycle events.
• Enable targeted experiences and controlled experiments through feature flags, cohort targeting, and reliable experiment assignment.
• Implement trustworthy event instrumentation and integrations that help teams understand acquisition sources, funnel performance, and customer behavior.
• Partner with Product and Data to clarify hypotheses, define measurement requirements, and assess results after launch.
• Improve performance and reliability across critical journeys, with particular attention to payment correctness, data consistency, and failure recovery.
• Own changes through design, implementation, testing, deployment, monitoring, and iteration.
• Use AI tools to accelerate development and troubleshooting while taking responsibility for correctness, security, and maintainability.

What You Need to Have

• Experience building and operating backend services in production, with strong experience in TypeScript.
• Strong foundations in API design, relational databases, data modeling, and automated testing.
• Understanding of asynchronous processing and distributed systems, including retries, idempotency, and consistency.
• Ability to translate product goals into pragmatic technical solutions and make clear trade-offs between speed and long-term maintainability.
• Familiarity with product analytics and experimentation, including how instrumentation affects the reliability of results.
• Experience diagnosing production issues using logs, metrics, and tracing.
• Clear communication, a collaborative approach, and the ability to take ownership in an evolving environment.
• Practical experience using AI in your engineering workflow and critically reviewing its output.
• Fluent English (written and spoken).

Nice to Have

• Experience with consumer subscriptions, payment providers, or entitlement systems.
• Experience with experimentation platforms, attribution, or lifecycle messaging.
• Familiarity with Go, cloud infrastructure, and event-driven architectures.

Compensation & Benefits

• Total Compensation Range: €50,400 — €79,200 EUR (reflects base, variable, and equity)
• Equity/stock options package