Full Stack Engineers

Boston, United States | Posted on 06/02/2026

• Salary $100,000 – $190,000 per year (Dependent on Experience)
• Province Massachusetts
• Country United States
• Postal Code 02108
• Number of Positions 1

Mastar Rec is a specialist recruitment and staffing agency supporting high-growth and technology-driven industries across the United Kingdom, the United States, and global markets
. We partner with organizations to deliver tailored staffing solutions focused on quality, integrity, and long-term value for both clients and candidates.

Mastar Rec is hiring a Full Stack Engineer – Fin Tech to support innovative financial technology platforms operating across the United States, building modern web applications and scalable cloud-based platforms.

This is an opportunity to contribute to high-impact digital products in sectors such as Fin Tech
, Healthcare Technology
, and SaaS
, within a fast-moving, innovation-driven environment that values clean code
, collaboration
, and technical excellence
.

3–5+ years of experience in software development
, with a strong focus on full-stack engineering
.

• Collaborate with frontend engineers to integrate seamless, performant user interfaces using React.js or similar libraries.
• Write clean, maintainable, and well-tested code aligned with modern software engineering best practices.
• Work cross-functionally with Product
  , Design
  , and QA teams to deliver high-quality features.
• Optimize system performance, troubleshoot production issues, and participate in code reviews
  .
• Design, build, and maintain scalable server-side applications and RESTful APIs using Node.js
  , Express
  , or similar frameworks.
• Contribute to architecture discussions
  , and refactor or modernize legacy systems when necessary.

• Strong hands-on experience with Node.js
  , Express
  , and API development
  .
• Solid understanding of SQL and No
  
  SQL databases (e.g.,
  PostgreSQL
  , MongoDB
  ).
• Experience with CI/CD pipelines and containerization (Docker).
• Familiarity with RESTful or Graph
  
  QL API design and integration.
• Proficient with version control systems such as Git and Git Hub
  .

• Frontend development experience using React.js
  , Next.js
  , or similar frameworks.
• Experience deploying and scaling applications in cloud environments (AWS, Azure, GCP).
• Knowledge of microservices architecture and distributed systems.
• Familiarity with Agile development methodologies and Test-Driven Development (TDD).
• Prior experience in Fin Tech
  , Healthcare
  , or SaaS product development is a plus.
• Competitive salary with performance bonuses
• Private health insurance and wellness support
• Learning & development allowance for certifications and upskilling
• Potential equity / stock options (depending on client)
• Collaborative, growth-oriented engineering culture
• Access to modern tech stack and cutting-edge tools