Java Developer
About this role
🔥 Java Developers... Ready to Build What’s Next? 🔥
We’re not hiring “just another developer.”
We’re bringing in sharp Mid and Mid-Senior Java Engineers to help launch something big, and strengthen the backbone of products already used globally.
At Onoff, growth isn’t a buzzword, it’s been our reality over the past few years. Revenue up. Teams expanding. Ambition even higher. Now we’re scaling our Tallinn crew and looking for people who want to build, influence, and leave a mark.
🚀 Why Onoff?
This is not a ticket-taking, feature-factory role. This is where engineering meets ownership.
💡 Lead & Influence – Shape architecture, challenge ideas, and drive decisions that matter.
📈 Real Impact – Work on core systems powering next-gen telecom SaaS.
🌎 Flexibility – Work in a way that actually works for you.
💰 Competitive Compensation – We invest in people who raise the bar.
🏖 Extra Time Off – Because performance needs recovery too.
🩺 Private Health Plan – We’ve got your back.
✈️ Travel Budget – Inspiration shouldn’t be limited to your desk.
📚 Continuous Learning – Stay evolving.
🎉 Culture That Feels Real – Smart people, good vibes and yes, we celebrate wins properly.
🔧 What You’ll Be Doing
• Building and scaling high-availability backend systems for a global communication platform
• Designing APIs and infrastructure that are fast, secure, and built to last
• Mentoring others while staying hands-on (no ivory tower leadership here)
• Collaborating across product, design, and engineering to ship meaningful solutions
• Owning things end-to-end: from idea → production → impact
🛠 What You Bring
• Strong Java expertise — Clean, efficient, production-grade code is your standard
• Experience with Docker, MySQL, AWS — You know how systems behave at scale
• A leadership mindset — You elevate others and aren’t afraid to challenge the status quo
• Sharp problem-solving — Complexity doesn’t scare you
• Product thinking — You care about why, not just how
• Startup energy — You move fast, adapt faster
👉 If you’re ready to build something new while strengthening something already powerful, we should talk.
Send your CV 📩 and let’s create what’s next, together.
Company at a glance
At OnOff, our goal is to reinvent the user experience in the world of telecommunications.
We are a team based in Paris and Tallinn, made up of 100 passionate people from around the globe.
In 2014, we launched the first version of a mobile app that finally allowed multiple phone numbers on a single device with the same SIM card. Since then, we’ve added numbers from more than 30 countries, as well as calling capabilities to nearly 150 destinations.
We’re also very proud of our “Onoff Business” solution, which streamlines fleet management by assigning professional lines directly to your employees’ smartphones.
Top Benefits
- Competitive Compensation
- Extra Time Off
- Private Health Plan
- Travel Budget
- Continuous Learning
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