Senior Backend Engineer · Transition to Go · Saily

Details

Saily is removing the hassle of staying connected while traveling by providing secure mobile data in more than 200 destinations. The company has millions of paying customers and hundreds of thousands of travelers browsing Saily at any given moment.

Saily fosters an AI-native Product Engineering culture in which engineers solve customer problems end-to-end, from idea to production, while AI agents support coding and repeatable tasks. The role focuses on backend development, product improvement, personalization, experimentation, analytics, and technical leadership.

Responsibilities

• Enhance the Saily product by developing and maintaining new features.
• Create features supporting multi-dimensional personalization, A/B experimentation, and analytics.
• Develop and maintain a high-quality codebase.
• Continuously improve code quality and performance.
• Mentor colleagues on development best practices and provide technical guidance.
• Influence the overall vision and long-range goals of the team.
• Perform research and development operations when required.
• Work as part of a cross-functional team and support smooth communication among team members.
• Collaborate with engineering, product, and design professionals from other teams.

This is a hybrid position requiring office attendance three times per week: Monday, Wednesday, and Friday.

Requirements

• More than 4 years of experience in backend development.
• Experience with one or more of the following backend languages: PHP, Python, C#/.NET, Java, or Kotlin.
• Familiarity with system design and the ability to select appropriate patterns based on context.
• Experience with Kubernetes and microservice architecture is a plus.
• Experience with SQL databases such as MySQL and PostgreSQL.
• Experience with NoSQL solutions such as Cassandra and Redis.
• Experience with Kafka.
• Passion for building easy-to-use and understandable APIs.
• Strong product mindset, with a focus on problems, outcomes, and impact rather than only tickets or tasks.
• Curiosity about AI and enthusiasm for working with AI agents.

Tools and Technologies

• Backend: Go, MySQL, Kafka, Docker, Kubernetes, AWS, Redis
• Frontend: Next.js, React.js, TypeScript, GraphQL, Tailwind CSS, Cloudflare Workers
• iOS: SwiftUI, Xcode, Combine, SPM, MVVM Architecture
• Android: Kotlin, Android Studio, Hilt, Coroutines, Jetpack Compose, MVVM Architecture
• AI tools: Claude Code, OpenAI Codex, OpenCode, Cursor with Composer

Benefits

• Online and in-person training programs, access to Coursera and Skillshare, mentorship, and internal career opportunities.
• Extra vacation days, sick leave, special-occasion leave, and parenting leave.
• Premium private health insurance available in Lithuania and Poland.
• Free subscriptions to Calm, Headspace, and Mindletic, plus resilience and mindfulness training and mental health events.
• In-house gyms, Multisport and Urban Sport cards, online workouts, and physical well-being consultations.
• Company workations abroad.
• The ability to work from anywhere when needed.
• Gifts for birthdays, work anniversaries, weddings, and new family members.
• Summer camps for children and flexible working arrangements for parents.
• Team-building activities and company events.
• Access to the Vilnius headquarters, including silent rooms, gyms, a game room, a music room, and a coffee bar.