Senior Full-Stack Engineer (Front-End Focus)
About the product
Intro
Start & timeline:
We’re hiring in advance. The project is currently in Phase 2, and the role starts with Phase 3, expected in early January 2027 (exact date TBC). We’ll keep you updated throughout the hiring process.
About the project:
We’re looking for a Senior Full-Stack Developer (frontend focus) to join a project for a Dutch bookkeeping platform that is modernizing its accounting core: moving from legacy single-entry logic to a database-backed double-entry model, with better ledger-code management and reconciliation. The live platform stays fully operational, so all changes are delivered safely within the existing architecture, together with the client’s engineering team.
This is a frontend-focused role: React and production MobX experience are the core, while Java/Spring knowledge helps you deliver features end to end. Full-time, approximately 19–23 weeks.
Technology stack
Frontend: React, MobX, TypeScript, JavaScript
Backend: Java, Spring, Hibernate, JPA, Redis
Database: MariaDB, PostgreSQL, Flyway
Testing: API/Cucumber, JUnit 5, WireMock, frontend/browser testing
CI/CD & hosting: SonarCloud, CI pipelines, Docker, Linux, WAR deployment, AWS S3
Tools: Jira, Confluence, Miro, Slack, Figma
Practices: feature flags, code reviews, small PRs, regular releases
Your team
You’ll join an established Techstack team and work closely with the client’s internal engineers. The team includes a Project Manager, Lead Software Engineer, QA Engineer, Senior Full-Stack Developer (this position), 2 Back-End Developers, plus the client’s Solution Architect and CTO. We work through daily stand-ups, sprint reports, regular code reviews, and close communication with the client’s developers.
Culture
We are committed to implementing high standards in the technology industry, and it is the fundamental mission of our work. To achieve this goal, the company and all its members are constantly evolving.
Each of us has the opportunity to contribute to the product, the company, the team, the industry, and our personal development. At Techstack, you have the option to choose from various growth opportunities that align with your interests:
- meetups, where you can share your knowledge and develop simultaneously by sharing your experiences within the company and local technical communities;
- roles such as a mentor or a technical lead. In any of these roles, you will assist junior professionals and share your knowledge and experiences with them.
- participation in our technical Guilds, where you can discuss technical solutions, approaches, and industry trends.
All of these elements contribute to shaping the culture and expertise within both our team and the company as a whole.
Your responsibilities
Develop and maintain features in existing React/MobX applications used by clients and bookkeepers.
Build administrative and configuration interfaces for ledger management and accounting workflows.
Implement searchable lists, forms with validation, role-based permissions, and reconciliation views.
Integrate frontend functionality with existing Java/Spring back-end APIs.
Support back-end development when needed for end-to-end delivery.
Make sure changes do not disrupt existing functionality in the live production platform.
Write and maintain frontend and browser-level automated tests.
Deliver changes through focused pull requests, feature flags, and regular releases.
Collaborate with the Tech Lead, back-end developers, QA, PM, and the client’s engineering team.
Participate in code reviews, daily stand-ups, demos, and acceptance testing.
It's about you
Solid commercial experience with Java.
Hands-on production experience with Spring and Hibernate.
Strong SQL skills and relational database design, preferably MariaDB or MySQL.
Experience with schema and data migrations using Flyway or similar tools.
Good understanding of transactions, database constraints, data integrity, and idempotent operations.
Experience writing unit and integration tests (JUnit 5, WireMock, or similar).
Experience maintaining and extending large existing codebases without breaking functionality.
Familiarity with feature flags, small focused PRs, and CI pipelines.
Comfortable working with Linux, application logs, and supporting production releases; hands-on experience with deployments, troubleshooting, and post-release monitoring is highly valued.
Ability to follow established architecture standards and collaborate through code reviews with the client’s developers.
Good spoken and written English for daily communication with the client.
Time zone: Europe/Kyiv or compatible with CET/CEST working hours.
What we have for you
Stable and long-term position in an experienced team.
Broad opportunities for professional and career growth, including professional challenges that encourage personal development, meetups, hackathons, professional communities, and more.
Horizontal connections and the absence of micromanagement foster a collaborative environment in which all team members are accessible to one another for any concerns.
Hubs in Kharkiv, Kyiv, Lviv, and Wrocław (Poland), or everything necessary for remote work.
Up to 50% compensation for the cost of educational courses and conferences to support professional development.
Free English language and business English courses.
20 days off and 7 sick days to support your health and well-being.
Legal and accounting support.
Appreciation gifts for significant events and occasions.
How to join Techstack
Pre-screening with a Talent Acquisition Specialist.
English check.
Technical interview and evaluation with Techstack engineers.
Candidate profile submission to the client.
Technical interview with the client’s engineering representatives (if requested).
About us
Techstack is a technology product engineering company that sets an example for high development standards in the IT industry. We empower each team member to influence the development of the product, company, and processes.
Learn more about Techstack
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