Senior Software Engineer

We’re looking for a Senior Software Engineer to join iOENT’s engineering team in Tallinn.

This is a hands-on senior role for an engineer who enjoys working on complex, high-load systems and taking real ownership of technical decisions. You’ll join a small team responsible for a business-critical product area, with the opportunity to modernise existing systems and influence architecture, scalability and reliability.

You’ll have the freedom to take solutions from design through to production, while working closely with a collaborative engineering team. Elixir/Erlang experience is an advantage, but we’re primarily looking for strong engineering fundamentals, system thinking and experience building production-critical software.

What you’ll do

• Design, develop and maintain scalable, high-performance applications using Elixir, TypeScript and related technologies.
• Take ownership of technical solutions from architecture and design through to production.
• Contribute to architectural decisions and help modernise existing systems.
• Build and improve distributed, high-load systems with a strong focus on reliability, scalability and performance.
• Design and implement integrations with third-party APIs and services.
• Troubleshoot complex production issues across functionality, performance and reliability.
• Write maintainable, well-tested code and contribute to engineering standards and best practices.
• Participate in code reviews and support the development of other engineers.
• Work closely with the team on the design and delivery of new features and projects.
• Use modern engineering and AI tools, including Claude Code, as part of the development workflow.

What we’re looking for

• 5+ years of hands-on software engineering experience.
• Strong system and architectural thinking.
• Experience working with distributed systems and high-load, production-critical applications.
• Proven experience building and shipping products into production.
• Strong ownership and ability to make technical decisions independently.
• Good understanding of reliability, scalability and application performance.
• Experience with API design and third-party integrations.
• Solid understanding of testing, CI/CD and production troubleshooting.
• Strong collaboration and communication skills.
• Professional working proficiency in English.
• Experience with Elixir/Erlang is a strong advantage, but not required.
• Experience with microservices and event-driven architectures is a plus.
• Experience with fintech, payments, finance or other complex, transaction-heavy products is a plus.

What We Offer

• Paid annual leave (as established by law).
• Birthday day off.
• 3 additional wellness days per year.
• Access to the Salu Digital Healthcare Program, plus the first three days of any claim for sick leave paid in full by the employer.
• Monthly sports compensation (€55/month via Stebby).
• Learning & Development budget in line with company policy.
• Team event budget.
• Hybrid working setup in Tallinn, with the option to work temporarily remotely for up to 60 days per calendar year.

Why this role and iOENT?

You’ll join a small team where individual contribution has visible impact and engineers have meaningful ownership over how solutions are designed and built. There’s significant technical depth to work with, as well as the opportunity to modernise an important product area and improve its architecture, reliability and performance.

If you’re a hands-on senior engineer who enjoys solving complex technical problems and taking solutions all the way from design to production, we’d like to hear from you.