Lead Ad Tech Engineer — Full-Stack (Go/Rails)

Titan OS Partnership; Barcelona; On-site; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Private health insurance

Central Barcelona office location

Competitive compensation

Friendly, diverse, international team

Job summary

Titan Operating System S.L. (Titan OS) in Barcelona seeks a senior full-stack engineer with a backend focus to design and build scalable, compliant ad-tech systems. You will participate hands-on while leading a team of engineers and shaping architecture across Rails, Go, and frontend components.

You will collaborate with Product, Data, Ad Ops and Sales to deliver reliable services, ensure low latency, and uphold GDPR and IAB TCF standards. Strong leadership and English proficiency are required.

Qualifications

• 5+ years of experience as a software engineer, full stack with a strong backend focus.
• Solid production experience with Ruby on Rails and Go.
• 2+ years leading an engineering team (tech lead or engineering manager), accountable for people and delivery.
• Experience designing APIs and high-performance, low-latency distributed systems.
• Strong knowledge of relational databases (PostgreSQL or MySQL) and caching/queueing (Redis, Kafka, SQS or similar).
• Experience with cloud (ideally AWS), containers and observability practices.
• Enough modern frontend knowledge (JavaScript/TypeScript, React or similar) to contribute and review code.
• Fluent English, spoken and written; it is our working language.

Responsibilities

• Lead, mentor and grow a team of engineers, including 1:1s, continuous feedback and career development.
• Take part in hiring and onboarding new team members.
• Define and uphold engineering practices: code review, testing, CI/CD, documentation and on-call.
• Plan and prioritise the team's work with Product, balancing roadmap, technical debt and operations.
• Design and evolve the services in the advertising stack: ad serving, programmatic integrations (OpenRTB, SSPs/DSPs), ad insertion (VAST/VMAP, SSAI) and reporting.
• Build hands-on, mainly in Ruby on Rails and Go, and contribute to the frontend when needed.
• Ensure performance, low latency and high availability of high-traffic services.
• Make sure systems comply with GDPR and the IAB TCF in how consent and identity are handled.
• Make and document technical decisions, and act as the Ad-Tech reference for other engineering teams.

Skills

Full-stack development

Backend focus

Team leadership

API design

PostgreSQL

MySQL

Redis

Kafka

AWS

JavaScript/TypeScript

React

Tools

Ruby on Rails

Go

OpenRTB/Ad tech

VAST/VMAP/SSAI

PostgreSQL

Redis

Kafka

AWS

Docker

Job description

Titan Operating System S.L. (Titan OS) in Barcelona seeks a senior full-stack engineer with a backend focus to design and build scalable, compliant ad-tech systems. You will participate hands-on while leading a team of engineers and shaping architecture across Rails, Go, and frontend components.

You will collaborate with Product, Data, Ad Ops and Sales to deliver reliable services, ensure low latency, and uphold GDPR and IAB TCF standards. Strong leadership and English proficiency are required.