Backend Engineer with analytical skills

Appunite; Województwo świętokrzyskie; Hybrid; PLN 179,000 - 246,000; Full time

Job summary

Appunite is seeking a skilled Kotlin/Java backend engineer to join our growing e-commerce platform team in Poland. The role focuses on designing, building, and maintaining microservices and data pipelines, with an emphasis on data-driven decision making and scalable systems.

You will work across the full lifecycle, pull KPI data, build dashboards, and communicate insights to business stakeholders. Remote-friendly with occasional on-site visits to Poznań or Warsaw 1–2 times per quarter.

Qualifications

• Solid commercial experience coding in Kotlin or Java.
• Build scalable microservices with Spring Boot.
• Write advanced SQL; BigQuery experience a plus.
• Experience building dashboards and presenting results.
• Polish and English at B2 level; good communication.
• Comfort with backend, some frontend, and networking basics.
• Ownership mindset and daily use of AI coding tools.

Responsibilities

• Design, build, and maintain Kotlin/Java microservices across full lifecycle.
• Pull data behind project KPIs such as GMV, transactions, returns.
• Build dashboards showing project impact after launches.
• Turn numbers into a clear business story for stakeholders.
• Collaborate with analysts, business and other product teams.
• Provide honest feedback and drive improvements.

Skills

Kotlin

Java

RESTful APIs

Spring Boot

SQL

BigQuery

Dashboards

Polish (B2)

English (B2)

Job description

The cooperation which stayed from startup to full-blown profitable product team!

Be a part of the biggest e-commerce platform in Poland and one of most recognizable in Europe with almost 200 mln MAU, which exists for over 20 years.

Our mission is to deliver the best possible customer experience across all platforms: web and mobile. From the moment customers visit our site to browsing, searching, comparing listings, purchasing, and post-purchase services, we ensure seamless, fast, and reliable operations.

What we offer

• Salary:

  • 16 000 - 22 000 PLN net on B2B - depending on your experience

  • ~13 390-18 413 gross/month employee contract- depending on your experience

• Growth in DDD and event-driven architecture, built into how our services work, plus Kotlin, BigQuery, microservices and AI tools in daily work

• Remote work with office access in Poznań, Warsaw, Kraków and Toruń. We ask for an on-site visit to Poznań or Warsaw 1-2 times per quarter.

• Have solid commercial experience coding in Kotlin or Java (and want to master Kotlin for new services)

• Build scalable microservices and RESTful APIs with Spring Boot

• Write advanced SQL on their own. This is the core analytical skill. Experience with BigQuery is a strong plus; the rest of GCP we can teach

• Have built dashboards and can present results so the right number is obvious at a glance

• Think like engineers, not only programmers: comfortable across backend, some frontend, and networking basics

• Take ownership: we’ll show you how the platform works, then expect you to find answers and propose solutions yourself

• Use AI tools (e.g., Copilot) daily for coding, debugging, and research

• Communicate effectively in Polish and English (at least B2)

What you’ll do

• Design, build, and maintain Kotlin/Java microservices across the full lifecycle, from development through production support

• Pull the data behind project KPIs such as GMV, transactions, and returns

• Build dashboards at the end of a project that show its real impact (for example, after launching listing grading: did time-on-page drop, and how did conversion change?)

• Turn numbers into a story the business and other teams can follow

• Work with analysts, business stakeholders, and, as the roadmap grows, other product teams across the platform

• Give honest feedback: your mixed skill set should help the team see what could be done better

What does the recruitment process look like?

1. Video interview with our People Team.

2. Technical interview with an engineer from the project (about 1h, no live coding), including the analytical part.

3. Short final check with Team Leader (20-30 min).

4. The decision, after which we can say "welcome on board".