Backend Engineer (TS/Node) — Hybrid Helsinki + Equity

Smartly; Helsinki; Hybrid; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Healthcare packages

Mental health services

Equity options

Performance-based rewards

Paid holidays & family leave

Work abroad up to 30 days annually

Career development opportunities

Job summary

Smartly in Helsinki is seeking a senior engineer to design, build, and maintain backend TypeScript/Node.js services and modern React frontends using TypeScript. You will drive architecture decisions, mentor peers, and collaborate across product, design, and engineering teams, with an expectation to work from the Helsinki office 3 days a week.

The role emphasizes reliability, scalability, and continuous improvement, with opportunities for growth and cross-team initiatives across Smartly's

Qualifications

• Strong experience building backend services with TypeScript and Node.js.
• Experience developing modern React applications using TypeScript.
• Solid understanding of distributed systems, APIs, microservice architectures, and cloud-native development practices.
• Experience writing and maintaining automated unit, integration, and end-to-end tests.
• Ability to independently drive projects from problem definition through delivery.
• Strong communication and collaboration skills, with experience working across multiple teams and functions.
• A customer-value mindset, pragmatic problem-solving skills, and a focus on continuous improvement.
• Interest in mentoring and supporting the growth of other engineers.
• Ability to work from the Helsinki office 3 days a week.
• Bonus: Python experience.

Responsibilities

• Design, build, and maintain backend services and frontend applications for campaign automation and optimization.
• Contribute to technical and architectural decisions that improve scalability, reliability, and developer experience.
• Develop and evolve services including Triggers, Ad Rotation, Smartly Actions, and Action Router.
• Collaborate with product managers, designers, and engineers across teams to deliver solutions that address customer needs.
• Own projects from planning through implementation, balancing short-term requirements with long-term maintainability.
• Improve system quality through automated testing, monitoring, and continuous improvement of engineering practices.
• Mentor engineers through code reviews, knowledge sharing, and technical collaboration.
• Contribute to cross-team initiatives and platform improvements that help shape Smartly’s target architecture.
• Work from the Helsinki office 3 days a week.

Skills

TypeScript

Node.js

React

Distributed systems

APIs

Testing

Project leadership

Communication

Mentoring

Cross-team collaboration

Python

Tools

TypeScript

Job description

Smartly in Helsinki is seeking a senior engineer to design, build, and maintain backend TypeScript/Node.js services and modern React frontends using TypeScript. You will drive architecture decisions, mentor peers, and collaborate across product, design, and engineering teams, with an expectation to work from the Helsinki office 3 days a week.

The role emphasizes reliability, scalability, and continuous improvement, with opportunities for growth and cross-team initiatives across Smartly's