Summary
Join Aperia Solutions, a fast-growing FinTech and managed consultancy building B2B accounts payable and payments platforms. You’ll 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
We’re seeking a Senior Full Stack Developer (Java, React) comfortable across backend, frontend, and cloud/infrastructure. You’ll 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 6 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 or .NET 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
- Bachelor’s Degree in Computer Science, Information Systems, or related field (or equivalent experience).
Job Type & Schedule
- Full time
- Monday to Friday
- Remote (need to live in VN)
Benefits
- Competitive Salary Package – Enjoy a rewarding income from day one.
- Security from the Start – Full salary during probation plus complete social insurance coverage.
- Premium Health Insurance – Comprehensive protection for you and your loved one (spouse/children).
- Family-Friendly Benefits – Monthly childcare support to make parenting easier.
- Generous Leave Policies – 15 days annual leave, 6 weeks paternity leave, and 10 days bereavement leave.
- Active Lifestyle – Join our vibrant clubs: Football, Billiards, Badminton, and E-sports...
Skills Required
- Minimum 6 years of hands-on experience with Java and Spring Boot, including MVC and/or WebFlux/Reactor
- Strong experience with React, REST APIs, HTML5, CSS3, and Bootstrap-based responsive user interfaces
- Experience with relational databases such as MySQL and PostgreSQL, including schema design, migrations, and performance tuning
- Experience with messaging systems such as RabbitMQ, AWS SQS, or AWS SNS and event-driven patterns
- Practical experience with AWS Lambda, ECS, S3, RDS, and SSM
- Knowledge of OAuth2, Spring Security, JWT, and policy-based authorization
- Testing experience with JUnit, Mockito, or similar frameworks
- Strong understanding of performance, security, best practices, and design patterns
- Experience with web services
- Bachelor's degree in Computer Science, Information Systems, or a related field, or equivalent experience
- Knowledge of WCF or .NET
- Fintech or payments domain knowledge, including ACH, NACHA, reconciliation, or FBO models
- Terraform or equivalent infrastructure-as-code experience and multi-environment infrastructure management
- Deep experience with reactive programming using Mono and Flux
- Observability experience with OpenTelemetry, distributed tracing, metrics, and logging
- Experience with multi-tier distributed applications
- Experience working in Agile or Scrum environments with distributed teams
- Strong communication skills
What We Do
Your success is our objective. We have more than a decade of service providing business intelligence solutions and applying extensive experience and knowledge to your business requirements. From its roots in the finance, banking, and the payments industry, Aperia expanded to become the preeminent provider of ETL, BI, and hosted solutions in a variety of industries. Aperia platforms scale with industry, processing massive volumes on time. The Software as a Service (SaaS) platforms support millions of end users creating billions of transactions per day, all with the speed and reliability required for business. The company’s management combines more than a century in finance, business consulting, rapid growth, and governance, as well as business intelligence, the company’s core function. Aperia knows that data holds power and providing the precision tools to release that power from data in any format is our passion, skill, and talent.
