Senior Backend Engineer, AI

Caspar Health

. Take full technological ownership of features from implementation through automated testing, release, and live operation .

Posted 10/22/2026full-timeRemote • GermanySenior💰 €78,000 - €88,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates expertise in developing scalable Ruby on Rails services, designing clean APIs, and managing background job processing while ensuring high-performance software delivery. Strong ability to collaborate with product managers and domain experts to translate complex requirements into maintainable solutions.

Highest-signal resume keywords

Ruby On Rails DevelopmentAPI DesignBackground Job ProcessingLLM Application DevelopmentAutomated Testing Strategies

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

Ruby On RailsAPI DesignData ModelingBackground Job ManagementLLM ApplicationsEvaluation PipelinesAgent WorkflowsAutomated TestingTechnical ReviewsOperational Monitoring

Soft Skills

Strong Communication SkillsCollaboration

Industry Keywords

Authorization ConceptsBilling WorkflowsTechnical Decision-MakingDelivery PracticesEngineering Standards

Tech Stack

Tools & technologies

RubyRuby on Rails

About the role

Key responsibilities & impact

Take full technological ownership of features from implementation through automated testing, release, and live operation
Develop scalable Ruby on Rails services, robust APIs, data models, and background jobs
Build and optimize LLM applications, evaluation pipelines, and agent workflows with repeatable quality checks
Collaborate with the Product Manager and domain experts to translate complex requirements into maintainable, high-performance software
Contribute through technical reviews, operational monitoring, and explicit technical decision-making
Shape shared delivery practices and establish modern testing and engineering standards across the team

Requirements

What you’ll need

Strong senior experience in building and maintaining complex systems using Ruby on Rails
Proven expertise in designing clean APIs and data models
Experience managing background job processing
Sound understanding of authorization concepts, billing workflows, and automated testing strategies
Practical experience building LLM applications, evaluations, and agent workflows
Ability and mindset to own functionality independently from initial design to live production
Strong communication skills to collaborate with product and domain experts and make technical trade-offs explicit
Must be eligible to work in Germany
Must be resident in Germany from the first day
Visa sponsorship and relocation assistance are not available

Benefits

Comp & perks

Remote-first with flexible working hours
Office optional in Berlin-Mitte
Up to 90 days a year outside of Germany
Monthly home office allowance
Additional meal subsidy
30 vacation days per year
Budget for learning & development, conferences, and coaching
High level of ownership and decision-making freedom
Access to all Caspar offerings for mental and physical well-being
Snacks, group sports sessions, drinks fridge, and humor