Senior Software Developer

Jobtailor; Helsinki; On-site; EUR 90,000 - 120,000; Full time

Job summary

Jobtailor in Helsinki is seeking a seasoned full-stack developer to build and optimize mobile and web apps using TypeScript, React, React Native, Next.js and Node.js. You will solve challenges in an agile setup and create new digital services from scratch with the latest tech.

Maintain and scale current solutions for long-term clients, collaborating with PMs, designers, and clients to align goals. Finnish and English fluency are required; a relevant degree is an advantage.

Qualifications

• Strong experience in modern JavaScript and full stack development with TypeScript, React, React Native, and Node.js.
• Ability to build scalable digital services across mobile and web.
• Frontend development: React, TypeScript, responsive UI, WCAG 2.2 AA, TailwindCSS, component libraries.
• Mobile & PWA development: React Native, push notifications, OTA updates, offline functionality.
• Backend development: Node.js, GraphQL, NestJS or Fastify.
• Databases & integrations: MySQL, PostgreSQL, MongoDB, Redis; RESTful APIs.
• QA & DevOps: testing (Jest, Playwright, Cypress), Git, CI/CD, Google Cloud.
• JWT auth, API keys, access restrictions.
• Client-facing communication with cross-functional teams.
• Relevant higher education degree is advantageous.
• Fluency in Finnish and English.

Responsibilities

• Develop and optimize mobile applications, utilizing frontend and backend 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.

Skills

JavaScript

TypeScript

React

React Native

Next.js

Node.js

GraphQL

NestJS

Fastify

Education

Bachelor's degree in Computer Science or related field

Tools

TailwindCSS

REST APIs

SQL / PostgreSQL / MySQL

MongoDB

Redis

Git

CI/CD

Jest

Playwright

Cypress

Google Cloud

Job description

Responsibilities

• 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

• 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.