Senior Backend Engineer - Go - Saily

📍 Warsaw, Poland

PLN 237,600-400,800 per year

SENIOR

✅ Hybrid

Tech Stack
Tag name is followed by "@" symbol and proficiency level value. About proficiency levels:

1-2 — basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;

3-6 — daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;

7-9 — you are an expert, you can teach others, you know all the pitfalls and tricks;

10 — exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.

AI @ 6 API @ 4 AWS Android CSS Cassandra @ 4 Claude Code Cloudflare Codex Docker Experimentation Go @ 4 GraphQL Hilt Jetpack Compose Kafka @ 4 Kotlin Kubernetes @ 1 MySQL @ 4 Next.js NoSQL @ 4 PostgreSQL @ 4 React Redis @ 4 SQL @ 4 Swift Tailwind CSS TypeScript iOS

Details

Saily is building a mobile connectivity product that provides secure mobile data in more than 200 destinations. The company fosters an AI-native Product Engineering culture in which engineers solve customer problems end to end, while AI agents help automate repeatable development tasks.

Responsibilities

Enhance the Saily product by developing and maintaining new features.
Create features supporting multidimensional 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 between 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

4+ years of product experience, preferably in a startup or scaleup environment.
Proven experience working with Go.
Experience with system design and knowledge of appropriate architectural patterns.
Experience with SQL databases such as MySQL and PostgreSQL.
Experience with NoSQL solutions such as Cassandra and Redis.
Previous experience with Kafka.
Experience building APIs that are easy to use and simple to understand.
Experience with Kubernetes and microservice architecture is a plus.
A 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.

Technologies

Backend: Go, MySQL, Kafka, Docker, Kubernetes, AWS, Redis
Frontend: Next.js, React.js, TypeScript, GraphQL, Tailwind CSS, Cloudflare Workers
iOS: SwiftUI, Xcode, Combine, Swift Package Manager, 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, access to Coursera and Skillshare, mentorship, and internal career opportunities.
Additional vacation days, sick leave, special-occasion leave, and parenting leave.
Premium private health insurance in Lithuania and Poland.
Free Calm, Headspace, and Mindletic subscriptions, plus resilience and mindfulness training.
In-house gyms, Multisport and Urban Sport cards, online workouts, and physical well-being support.
Company workation opportunities.
The option to work from different locations.
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.