Senior Backend Engineer — AI-Driven Growth & Subscriptions

Sword; Portugal; On-site; EUR 50,000 - 79,000; Full time

Job summary

Sword is hiring a Senior Backend Engineer in Consumer Growth to build services that help people discover products, become paying members, and stay engaged. You will work with Product, Data, Design, and Marketing to ship reliable growth experiences across web, Android, and iOS.

The role emphasizes scalable architecture, experimentation, and strong ownership, with attention to payment accuracy and security. Remote collaboration and advanced AI tooling are integral.

Qualifications

• Experience building and operating backend services in production with TypeScript.
• Strong API design, relational DBs, data modeling, and automated testing.
• Understanding asynchronous processing and distributed systems, incl. 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.

Responsibilities

• 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 and entitlements.
• Enable targeted experiences and controlled experiments through feature flags and cohort targeting.
• Implement trustworthy event instrumentation and integrations to understand acquisition sources and funnel performance.
• Partner with Product and Data to clarify hypotheses and assess results after launch.
• Improve performance and reliability across critical journeys, with focus on data consistency and failure recovery.
• Own changes through design, implementation, testing, deployment, monitoring, and iteration.

Skills

TypeScript

API design

Relational databases

Automated testing

Distributed systems

Product analytics

Logging & tracing

Ownership

AI in engineering

Fluent English

Tools

Go

Cloud infrastructure

Event-driven architectures

Job description

Sword is hiring a Senior Backend Engineer in Consumer Growth to build services that help people discover products, become paying members, and stay engaged. You will work with Product, Data, Design, and Marketing to ship reliable growth experiences across web, Android, and iOS.

The role emphasizes scalable architecture, experimentation, and strong ownership, with attention to payment accuracy and security. Remote collaboration and advanced AI tooling are integral.