Junior Back End Developer (Ruby)
Data.ai
Software Engineering
Lisbon, Portugal
Posted on Nov 25, 2025
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About this role:
At Sensor Tower, we don’t just want you to write code; we want you to build the technical and product ownership that makes your work meaningful. We are looking for a talented Junior Back End Developer to join a high-priority strategic initiative.
In this role, you will build systems to track and analyze how major conversational Large Language Models (LLMs) perceive apps, brands, and digital entities. You will join a high-performing team to launch and quickly iterate on this new product, with high expectations for your work paired with a strong emphasis on fast career development and growth. We have a strong track record of leveling up talented juniors quickly, and this role offers a rare opportunity to pair closely with senior leadership on a greenfield project.
Our Engineering Culture
We believe that "Simplicity is a prerequisite for reliability." We are looking for engineers who align with our core values:
- Simplicity: We avoid over-engineering. We prefer the tools we already have and the most straightforward solutions over "shiny new toys."
- Quality: We write code that is a pleasure to read because we know code is written once but read many times. We don't cut corners, and we polish to a high level before shipping.
- Extreme Ownership: We don't just do the minimum. We expect you to understand the "why" behind your work and own the ultimate goal of fixing problems at their root cause, avoiding temporary band-aids.
- Prioritization: We focus relentlessly on what is important, not just what is urgent.
What You Will Do
- Build New Insights Features: You will build and maintain reliable, high-performance pipelines to aggregate and analyze data from various AI models.
- Own the Full Development Lifecycle: You will participate in the complete development lifecycle through design, implementation, and release. You won't consider a project done just because it was merged; you will own the follow-up to ensure no tech debt accumulates.
- Collaborate Cross-Functionally: You will work closely with cross-functional teams, ensuring you understand the end-to-end process to design the correct systems.
- Drive Future Strategy: Long term, you will work on additional strategic engineering projects to continuously make a business impact and grow our footprint.
Experience We Are Looking For
- Stack Alignment:
- Preferred: Knowledge of Ruby on Rails and the broader Ruby ecosystem is a large plus. Alternatively, demonstrated proficiency in Python or similar languages, with a willingness to cross-train in Ruby, is acceptable.
- Nice-to-have: Experience with Clickhouse or other OLAP databases; MongoDB or other document stores; Sidekiq or other asynchronous task runners.
- Technical Foundation: A strong grasp of algorithms, RESTful systems, and API design. Experience with data analysis and data pipelining is ideal.
- Github/Portfolio: A portfolio of meaningful Github contributions, open-source work, or interesting personal projects that demonstrate you can build working software.
- Curiosity & Drive: A proactive approach to digging into sources yourself rather than relying on second-hand information, and an eagerness to understand why a project is valuable before you start coding.
Why Join?
We don’t want you to be here just for a job. We want you here because you enjoy the problems we solve and want to make an impact. If you are ready to do high-quality work, focus relentlessly on the most important priorities, and grow your career by solving hard problems, we want to hear from you.