Backend Engineer (AI)

TL;DR

Backend Engineer (AI): Building and optimizing high-scale backend services for Flo's personalization and AI platform, with an accent on the User Profile service (20k RPS, <15ms latency) and bridging raw user data to ML feature stores. Focus on designing and implementing data pipelines for AI/ML systems, enabling inner-source contributions, and ensuring healthcare compliance.

Location: Flexible office + home working, up to 2 months a year working abroad

Salary: €8,000–€12,000 EUR gross per month

Company

hirify.global is the world’s #1 health & fitness app, backed by a $200M investment, on a mission to build a better future for female health.

What you will do

• Develop new features for the User Profile service, powering personalization, experimentation, and Flo Conversational AI.
• Build User Profile 2.0 capabilities, including historical data arrays and ML feature store integration.
• Design and implement data pipelines for AI/ML systems for personalized content generation and predictive models.
• Enable inner-source contributions by establishing guidelines, quality gates, and architectural standards.
• Maintain architectural oversight of core components while enabling safe, autonomous contributions from product teams.
• Ensure compliance with healthcare regulations (HIPAA, SOC 2, GDPR) and implement privacy-first design patterns.

Requirements

• 7+ years of professional experience building distributed backend systems at scale.
• Fluency in Scala, Java, or Python – with willingness to work primarily in Scala.
• Deep experience with AWS services, particularly DynamoDB, EKS, and serverless architectures.
• Strong understanding of observability – logging, metrics, tracing, and alerting.
• Experience building high-throughput, low-latency APIs serving millions of users.
• Solid understanding of databases (SQL and NoSQL) and experience designing APIs that prioritise reliability and performance.
• Experience with code review, mentorship, and establishing engineering standards across teams.
• Strong communication skills – you can collaborate effectively with multiple teams and explain technical decisions clearly.

Nice to have

• Experience with ML infrastructure, feature stores, or data platforms that serve AI/ML workloads.
• Familiarity with data pipelines and integration patterns for machine learning systems.
• Experience with inner-source or open-source contribution models and governance.
• Experience with platform/infrastructure teams supporting multiple product teams.
• Healthcare compliance framework experience (HIPAA, SOC 2, GDPR).
• Feature flagging, A/B testing, or experimentation platform experience.
• Experience in the MedTech or HealthTech domain.

Culture & Benefits

• Competitive salary and annual reviews with opportunity to participate in Flo’s performance incentive scheme.
• Paid holiday, sick leave, and female health leave; enhanced parental leave and pay.
• Accelerated professional growth through world-changing work and learning support.
• Flexible office + home working, up to 2 months a year working abroad.
• 5-week fully paid sabbatical at 5-year Floversary.
• Flo Premium for friends & family, plus health, pension and wellbeing perks.
• Hiring based on merit, skill and what you bring to the role, with a commitment to diversity, equity, and inclusion.