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.

Main Responsibilities

Build a completely new sophisticated microservices system for the new eSim Product

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

Use AI agents for specifications, coding, analysis, testing, and iteration

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

Core Requirements

Experience working with Go (4+ years) OR with any of the following backend languages: PHP, Python, C#/.NET, Java, Kotlin

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, PostgreSQL) and NoSQL (Cassandra, Redis) solutions

Previous experience with Kafka

Passionate about building APIs that are easy to use and simple to understand

Strong product mindset: focus on problems, outcomes, and impact—not just tickets or tasks

You are curious about AI and excited to work with agents