Full Stack Java Engineer (React)

Summary Join Aperia Solutions a fast-growing FinTech and managed consultancy building B2B accounts payable and payments platforms. Youll join a mid-size distributed team working across the full stack from Terraform infrastructure to Spring Boot services to React interfaces and database migrations. Aperia serves banks processors payment facilitators merchant service providers ISOs and government entities. This role offers technical ownership a collaborative culture and opportunities to shape product and architecture.

Job Description Were seeking a Senior Full Stack Developer comfortable across backend frontend and cloud/infrastructure. Youll design build and maintain secure high-performance payment systems and integrations. The ideal candidate has strong Java/Spring Boot experience React front-end skills relational database expertise (MySQL/Postgres) messaging/event-driven architecture experience and practical AWS and infrastructure-as-code exposure. Testing discipline API security (OAuth2/JWT) and familiarity with distributed tracing are important.

Core Responsibilities

• Design create maintain and optimize applications using Spring Boot (MVC and WebFlux) React and the Microsoft/Java tech stack where applicable.
• Translate business requirements into functional secure and scalable solutions.
• Build and maintain APIs (REST) integrate messaging queues and implement async/event-driven patterns.
• Manage DB schema design and migrations for MySQL/PostgreSQL; optimize queries and performance.
• Participate in infrastructure-as-code efforts (Terraform or equivalent) and deploy to multi-environment AWS (ECS Lambda RDS S3 SSM).
• Secure APIs using OAuth2/Spring Security with JWT and policy-based authorization.
• Maintain upgrade and refactor existing codebases to improve efficiency and performance.
• Write and maintain unit and integration tests (JUnit Mockito) and support CI/CD and observability (OpenTelemetry/distributed tracing).
• Collaborate with product QA and distributed engineering teams; participate in Agile sprints and code reviews.
• Ensure error-free code that follows best practices design patterns and security standards.
• Mentor peers investigate and resolve production issues and support continual improvement.

Functional Responsibilities

• Work with Business Analysts and US-based stakeholders to clarify requirements.
• Propose technical approaches and detailed implementation plans.
• Implement daily tasks investigate issues and support team members to deliver high-quality work.
• Perform unit and cross testing; document results.
• Conduct technical research and internal training.
• Other duties as assigned.

Required Technical Skills & Experience

• Minimum 4 years hands-on experience with Java and Spring Boot (MVC and/or WebFlux/Reactor).
• Strong experience with React REST APIs HTML5 CSS3 and Bootstrap-based responsive UI.
• Solid experience with relational databases (MySQL PostgreSQL): schema design migrations and performance tuning.
• Experience with messaging systems (RabbitMQ AWS SQS/SNS or similar) and event-driven patterns.
• Practical AWS experience (Lambda ECS S3 RDS SSM).
• Knowledge of OAuth2/Spring Security JWT and policy-based authorization.
• Testing discipline with JUnit Mockito or similar frameworks.
• Strong understanding of performance security best practices and design patterns.
• Experience with Web Services; familiarity with WCF is a plus but not required.

Desirable Experience (will separate you from the rest)

• Fintech/payments domain knowledge (ACH NACHA reconciliation FBO models).
• Terraform or equivalent IaC and multi-environment infrastructure management.
• Deep experience with reactive programming (Mono/Flux).
• Observability experience: OpenTelemetry distributed tracing metrics and logging.
• Hands-on experience with multi-tier/layer distributed applications.
• Comfortable working in Agile/Scrum environments and with distributed teams.
• Strong communication skills.

Education or Certifications

• Bachelors Degree in Computer Science Information Systems or related field (or equivalent experience).

Eligibility Requirements

• Must be willing to submit to a background investigation and drug test as part of the selection process.

Job Type & Schedule

• Full time
• Monday to Friday
• Remote

Benefits

• Health insurance; Health savings account
• Dental insurance; Vision insurance
• 401(k) matching; Life insurance
• Paid time off; Parental leave; Disability insurance
• Childcare assistance; Education reimbursement
• Fitness membership; Volunteer time off