Senior Software Developer

Hion

Senior Software Developer creating digital services and solutions for clients at Hion Digital. Collaborating in agile teams to deliver innovative web and mobile applications.

Posted 6/25/2026full-timeHelsinki • 🇫🇮 FinlandSenior💰 €4,000 - €5,000 per monthWebsite

Tech Stack

Tools & technologies

CloudCypressGraphQLJavaScriptJestMongoDBMySQLNext.jsNode.jsPostgresReactReact NativeRedisTypeScript

About the role

Key responsibilities & impact

Develop and optimize mobile applications, utilizing both front-end and back-end technologies such as TypeScript, React, React Native, Next.js, and Node.js.
Solve challenges and work in an agile environment.
Build brand new digital services from scratch using the latest tech stack.
Continuously modernize, maintain, and scale existing solutions for long-term clients.
Collaborate with project managers, designers, and fellow developers while also working directly with clients to understand their needs and goals.
Participate in quality assurance and actively engage in code reviews.

Requirements

What you’ll need

Strong experience in modern JavaScript and full stack development, particularly with TypeScript, React, React Native, and Node.js.
Understanding of high-quality, scalable digital services across both mobile and web platforms.
Experienced with frontend development: React, TypeScript, responsive user interfaces, accessibility (WCAG 2.2 AA), TailwindCSS, and component libraries.
Experienced with mobile & PWA development: React Native, mobile-specific capabilities (e.g. push notifications, OTA updates, NFC), Progressive Web App solutions, and offline functionality.
Experienced with backend development: Node.js, GraphQL, and frameworks such as NestJS or Fastify.
Knowledge of databases & integrations: e.g. MySQL, PostgreSQL, MongoDB, Redis, as well as RESTful APIs and HTTP fundamentals.
Familiarity with quality assurance & DevOps: testing (e.g. Jest, Playwright, Cypress), Git, CI/CD, and cloud environments such as Google Cloud.
Understanding modern application development best practices, including JWT authentication, API key management, and access restrictions.
Ability to work effectively with clients, partners, and cross-functional stakeholders, and communicate proactively within project teams.
A relevant higher education degree is considered an advantage.
Fluency in both Finnish and English.

Benefits

Comp & perks

Flexible remote work possibilities
Professional development opportunities

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills & Tools

TypeScriptReactReact NativeNext.jsNode.jsGraphQLNestJSFastifyMySQLPostgreSQL

Soft Skills

collaborationcommunicationproblem-solvingagile methodologyclient engagementquality assurancecode reviewcross-functional teamworkproactive communicationstakeholder management