Backend Engineer | Senior | Go | Saily

At Saily, we’re removing the hassle of staying connected while traveling — no roaming fees, no plastic SIM cards, just lightning-fast, secure mobile data in 200+ destinations. Saily has millions of paying customers and hundreds of thousands travelers browsing through Saily at any given moment.

To build the best product for our customers we foster
AI-native Product Engineering culture
, where:

• The Engineer is the builder, who is responsible for solving customer problems end-to-end (idea to production)
• AI Agents are the enablers who write most of the code and solve repeatable tasks to help the Engineers maximize their impact
• Everyone contributes to making Saily effective by suggesting new areas for improvement to delegate to agents and then implementing the changes
• Curiosity, learning and sharing are everyone's responsibility
• Customer, having a comfortable, connected, hassle-free journey, is never lost from the focus

We value growth over comfort, contribution over hierarchy, and impact over process.
At Saily, we believe in giving sharp people context, autonomy, and AI as their multiplier to allow them to just do their best work.

• Enhancing the Saily product by developing and maintaining new features.
• Create features to support layers of multi-dimensional personalization, A/B experimentation, and analytics.
• Develop and maintain a high-quality codebase.
• Seek to improve code and performance constantly.
• Mentor colleagues on development best practices & provide technical guidance.
• Exercise influence on the overall vision and long-range goals of your team.
• Perform R&D operations whenever required.
• Work as part of a cross-functional team and help to ensure smooth communication between all team members.
• Collaborate with engineering, product, and design professionals from other teams.

• Please keep in mind that this position requires office attendance 3 times a week!

• Over 4 years of experience in backend development.
• Preferably with a background in Python, PHP, or Ruby languages.
• System design is nothing new to you, and you know what patterns to use, when, and why.
• Previous experience in working with K8s and microservice architecture is a plus.
• Previous experience with SQL (MySQL, Postgre
  
  SQL) and No
  
  SQL (Cassandra, Redis) solutions.
• Previous experience with Kafka.
• Passionate about building APIs that are easy to use and simple to understand.
• A collaborative mindset where you love to discuss, rethink, and redesign your ideas that create shared success within your team and the company.

• Backend: Go, MySQL, Kafka, Docker, Kubernetes, AWS, Redis
• Frontend: Next.js, React.js, Type Script, Graph
  
  QL, Tailwind CSS, Cloudflare Workers
• iOS: Swift
  
  UI, Xcode, Combine, SPM, MVVM Architecture
• Android: Kotlin, Android Studio, Hilt, Coroutines, Jetpack Compose, MVVM Architecture
• AI tools: Claude Code, OpenAI Codex, Open Code, Cursor with Composer

• Gross Salary  PLN/month.

Work alongside global experts to build world-leading cybersecurity tools, impacting millions of users around the world.

Boost your skills via our extensive training programs (online and offline) & other resources. Benefit from mentorship and career-switch opportunities to grow within the company.

Enjoy the flexibility with 3 office days and working from home for the remaining 2.

Recharge with a change of scenery – choose work from any location when you feel a need to power your creativity and drive.

Fuel your active lifestyle with online workouts led by our Physical Well-Being experts. Unlock a variety of sports and wellness facilities, like gyms, swimming pools, and fitness classes, with the Multisport card.

Nurture your mind with free psychologist consultations, dedicated mental health events, and premium access to top-rated wellness apps like Calm, Headspace, and Mindletic.

Receive private health insurance giving you peace of mind for your health needs.

Celebrate life’s big moments with special gifts from us on your birthday, anniversary, and other major…