Senior Full-Stack Engineer (Hybrid) — AI Analytics

Smartly; Helsinki; Hybrid; EUR 110,000 - 165,000; Full time

Benefits offered by this job

Healthcare support

Paid holidays and family leave

Equity opportunities

Career development opportunities

Job summary

Team Reach at Smartly in Helsinki, hybrid, seeks a hands-on senior contributor to shape technical decisions across data interfaces, backend services, and models. You will drive initiatives from an initial question to a reliable production solution, partnering with Product and Design to meet customer needs.

You’ll lead across frontend, backend, data and models, invest in testing and validation, and mentor others while strengthening our engineering practices and AI-guided development approach.

Qualifications

• You’ve designed, shipped, and operated substantial production software and can explain the decisions behind it.
• You’re comfortable across frontend, backend, data, and models, with willingness to go deeper where needed.
• You understand how APIs, data modeling, algorithms, application state, and testing affect correctness, performance, and maintainability.
• You break unfamiliar problems apart, make assumptions explicit, identify counterexamples, and establish whether a solution is sound.

Responsibilities

• Own outcomes. Work with Product and Design to clarify customer needs, choose an approach, and carry initiatives through delivery and follow-up.
• Build across the stack. Develop data exploration interfaces, backend services and APIs, and the data models and computations connecting them.
• Make complex logic reliable. Investigate assumptions, reason through edge cases, and establish how to test and validate algorithms and statistical business logic.
• Drive coordinated delivery. Turn ambiguous goals into manageable steps, agree priorities, coordinate dependencies, surface risks early, and keep colleagues informed.
• Build shared understanding. Listen to different perspectives, explain trade-offs clearly, and help engineering and business stakeholders reach decisions.
• Strengthen engineering practice. Contribute through architecture discussions, thoughtful reviews, documentation, mentoring, and improvements to how we work.

Skills

Senior engineering experience

Full stack capability

Strong fundamentals

Analytical reasoning

Collaborative leadership

Practical AI judgment

Tools

TypeScript

React

Node.js

Job description

Team Reach at Smartly in Helsinki, hybrid, seeks a hands-on senior contributor to shape technical decisions across data interfaces, backend services, and models. You will drive initiatives from an initial question to a reliable production solution, partnering with Product and Design to meet customer needs.

You’ll lead across frontend, backend, data and models, invest in testing and validation, and mentor others while strengthening our engineering practices and AI-guided development approach.