Backend Engineer - Golang

JobCubby; Kraków; On-site; PLN 150,000 - 210,000; Full time

Job summary

Sensor Tower in Kraków is seeking a backend engineer to help build fast, reliable systems for a market intelligence SaaS platform. You’ll work with Go, SQL, and our data-heavy stack across design, implementation, and production optimization.

You’ll contribute from day one, participate in full development life cycle, and tackle parsing, data aggregation, API design, and performance improvements. Collaboration with experienced engineers and QA is expected, with emphasis on quality and ownership.

Qualifications

• 3+ years of backend Go experience with a strong focus on performance and reliability.
• Strong SQL skills (Postgres/ClickHouse) and ability to write complex queries.
• Commitment to testable, maintainable code and ownership of fixes.
• Ability to see the product through user’s eyes and ship high-quality features.

Responsibilities

• Improve and build new features for a market intelligence SaaS platform.
• Participate in full development life cycle: design, implement, polish, release.
• Work on parsing, data aggregation, API design, refactoring, and performance optimization.
• Create and optimize complex database queries for data analysis.

Skills

Go programming

SQL

Testing/quality code

CI/CD

AI tools in development

Docker/Kubernetes

Product/data mindset

Tools

PostgreSQL

ClickHouse

MongoDB

Elasticsearch

RabbitMQ

GitLab

Docker

Kubernetes

Job description

About this role:

At Sensor Tower, we process tens of terabytes of data to power insights used by thousands of customers. We’re looking for curious, motivated engineers who want to grow their skills while helping us build fast, reliable systems that make data easy to access and understand.

You’ll work closely with experienced engineers, contribute to meaningful features from day one, and learn how large-scale systems are designed, built, and optimized in production.

If you enjoy learning, solving problems, and shipping real software that users rely on, we would love to meet you.

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’ll do:

• Improving and building new features for an app market intelligence SaaS platform focused on the SMBs (AppMagic by Sensor Tower).
• Participate in the full development life cycle, including design, implementation, quality polish, and release.
• Work on a variety of tasks, such as parsing, data aggregation, API design, refactoring, and performance optimization.
• Create and optimize complex database queries for data analysis and modification.
• Perform code reviews, and suggest improvements to tools and processes.

Backend stack: Golang, PostgreSQL, ClickHouse, MongoDB, Elasticsearch, RabbitMQ, GitLab, Docker, Kubernetes.

What we are looking for:

• +3 years of experience with Go (if you have lesser years of experience but have meaningful github contributions and other coding samples, this will be taken into consideration).
• Strong SQL skills (Postgres/ClickHouse). You know when to rely on an ORM and when to write raw SQL, and you're comfortable writing and debugging complex queries.
• Focusing on quality by writing testable code that simplifies debugging and ensures long-term reliability.
• Ability to see the product through the user’s eyes and a passion for product excellence.
• 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.
• Experience with CI/CD, docker, k8s as a plus.
• Ability to pass technical interview both in Russian & English.
• Hands-on, thoughtful use of AI tools in development.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.