Senior Full-Stack Engineer (Front-End Focus)

Techstack; United States; Remoto; USD 120.000 - 180.000; Tempo pieno

Vantaggi offerti da questo lavoro

Stable and long-term position

Broad opportunities for professional/g

Remote work as needed

Up to 50% education/course support

Free English courses

20 days off and 7 sick days

Legal and accounting support

Appreciation gifts

Descrizione del lavoro

Techstack is seeking a Senior Full-Stack Developer (frontend focus) to modernize a Dutch bookkeeping platform with a React/MobX frontend and Java/Spring backend. You’ll work closely with client engineers, deliver features end-to-end, and participate in code reviews and releases.

This is a full-time role with remote-ready arrangements and a multi-week project horizon. Ideal candidates have strong React/MobX experience, solid Java/Spring background, and a proactive approach to collaboration,

Competenze

• Solid commercial experience with Java and Spring.
• Strong SQL skills and relational DB design (MariaDB/MySQL).
• Experience with Flyway migrations and data integrity.
• English language for daily client communication.

Mansioni

• Develop and maintain React/MobX applications for clients.
• Build admin UI for ledger management and workflows.
• Create searchable lists and forms with validation.
• Implement role-based permissions and reconciliation views.
• Integrate frontend with Java/Spring back-end APIs.
• Support back-end work for end-to-end delivery.
• Ensure changes do not disrupt live production.
• Deliver changes via PRs, feature flags, and releases.
• Collaborate with client team and QA in code reviews.

Conoscenze

React

MobX

Java

Spring

SQL

CI pipelines

Unit testing

English communication

Strumenti

Hibernate

MariaDB

MySQL

Flyway

JUnit 5

WireMock

Linux

Descrizione del lavoro

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.

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’re 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, 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.
• 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 havefor 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.

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.