Senior Java Engineer
Job Overview
We’re looking for a strong Mid OR Senior Java Engineer to shape and scale the backend of our core product, KaiKai Lock Screen, used by millions of users every day.
We’re looking for someone who:
- Dreams Big: ambitious, passionate, and out to achieve massive goals
- Customer‑centric: we care about our customers and strive to provide them with the best solutions
- Celebrates both Success & Failure: rejoicing the wins but also reflecting, learning & improving proactively when there are defeats
- Honesty and Integrity: we appreciate respectful feedback
- Problem Solver: you’re a fixer and not a complainer
- Actionable: work and make smart decisions fast with conviction
What you’ll do:
- Design, develop, and maintain backend services for KaiKai Lock Screen and CMS
- Build scalable systems for large‑scale data processing and real‑time content delivery
- Contribute to architecture and system design improvements
- Maintain high code quality through testing, code reviews, and engineering best practices
- Work with distributed and event‑driven systems to build scalable backend solutions
- Improve system performance, reliability, and efficiency for a high‑traffic product
- Support integrations with external services and third‑party systems
- Collaborate closely with Product, Content, and Data teams to deliver meaningful features
- Share knowledge and contribute to continuous team improvement
What you’ll need:
- Strong experience in Java backend development
- Experience building scalable and high‑performance backend systems
- Familiarity with event‑driven systems (Kafka) and modern architectures
- Knowledge of relational databases and SQL
- Ability to take ownership and drive solutions
- Good communication within the team (Polish and English required)
- Experience with high‑traffic systems is a plus
What you’ll enjoy:
You’ll work with a seasoned leadership team, backed with expertise across strategic domains, within a culture that values learning, impact, and cross‑functional collaboration.