Senior Full Stack Engineer (Reach)

Location: Helsinki, Finland; hybrid with three office days per week

Company

hirify.global is an AI-powered advertising technology company providing an integrated media, creative, and intelligence platform for brands and advertisers.

What you will do

• Work with Product and Design to clarify customer needs, select approaches, and own initiatives through delivery and follow-up.
• Build data exploration interfaces, backend services, APIs, data models, and computations across the stack.
• Investigate assumptions, edge cases, and validation methods for algorithms and statistical business logic.
• Coordinate priorities, dependencies, risks, and delivery across engineering and business stakeholders.
• Explain technical trade-offs, build shared understanding, and support decision-making.
• Contribute to architecture discussions, code reviews, documentation, mentoring, and engineering practice improvements.

Requirements

• Senior experience designing, shipping, and operating substantial production software, with the ability to explain technical decisions.
• Full stack capability across frontend, backend, data, and models, with depth in selected areas and willingness to go deeper as needed.
• Strong understanding of APIs, data modeling, algorithms, application state, testing, correctness, performance, and maintainability.
• Analytical reasoning: make assumptions explicit, identify counterexamples, and establish whether solutions are sound.
• Collaborative leadership, including asking useful questions, building agreement, giving and receiving feedback, and helping colleagues make progress.
• Practical AI judgment: assess generated output critically and verify changes through testing and investigation, including security, maintainability, and complexity considerations.
• Curiosity and willingness to learn the product domain are essential.

Nice to have

• Experience with analytical products, statistics, or algorithmic systems.
• Experience with technologies beyond TypeScript, React, and Node.js.

Culture & Benefits

• AI-assisted development is used for exploration, implementation, testing, and review, while engineers remain responsible for understanding, validating, and maintaining shipped work.
• Healthcare and mental health support.
• Paid holidays and family leave.
• Equity opportunities and career development opportunities.
• Hands-on technical leadership and collaboration within a multinational, diverse organization.

Hiring process

• Recruiter conversation about experience and the role, followed by a team lead discussion about expectations and ways of working.
• Technical interviews covering coding, system design, and architecture.
• Final conversation with engineering leadership.