Senior Software Engineer - Full Stack (React+Java) REQ_133

3Pillar; All (MO); Remote; USD 120,000 - 190,000; Full time

Benefits offered by this job

Remote-first environment

Global team collaboration

Well-being program

Career growth opportunities

Diversity & inclusion emphasis

Job summary

3Pillar is seeking a senior software engineer to design and deliver a modern full-stack platform. You’ll work on React 19 on the frontend and Java 25 with Spring Boot 4 on the backend, crafting scalable solutions and guiding architectural decisions across Avalon engagements.

You will mentor teammates, participate in agile ceremonies, and responsibly use AI-assisted tools like GitHub Copilot and OpenSpec to ensure high-quality software delivery.

Qualifications

• Experience delivering enterprise-scale frontends with React 19 and modern tooling.
• Strong understanding of frontend state management and routing.
• Familiarity with test-driven development and unit testing.
• Proficient in secure, scalable, and maintainable client-side code.
• English proficiency and experience in Agile software delivery.

Responsibilities

• Lead client-facing frontend development with a focus on quality and performance.
• Collaborate with architects and engineers to design scalable features.
• Plan, estimate, and deliver work using project methods and tools.
• Gather requirements and communicate progress to stakeholders.
• Mentor teammates and contribute to engineering practices.

Skills

React 19

JavaScript/JSX

Redux Toolkit

React Router

Axios

Okta React

Vitest

ESLint/Prettier

Nginx

GitHub Copilot

Tools

Vite

Material UI (MUI)

Emotion

React Redux

OpenSpec

GitHub Actions

Nginx

OKTA OAuth 2.0

Job description

3Pillar is an AI transformation partner on a mission to help enterprises build the AI-native products and intelligent agents that will define the next era of business. With teams across North America, Europe, Latin America, and Asia, we work with the most ambitious companies in financial services, healthcare, media, and technology - helping them move faster, modernize boldly, and compete on their own terms. Our HelixAI platform and Helix Pods delivery model put our engineers at the center of real agentic transformation - doing work that is open, portable, and built to last. We are building the future of enterprise AI.

Role Overview

Elevate your expertise to new heights at 3Pillar, the premier destination for trailblazing senior software engineers like yourself. On the Avalon engagement, you'll help build and evolve a modern full-stack platform - React 19 on the frontend and Java 25 with Spring Boot 4 on the backend - working alongside industry leaders to deliver transformative solutions for the business. Your role extends beyond the realm of code composition; you will architect solutions that reshape how Avalon's teams and customers work. Join us and spearhead the charge toward a tech future that transcends the ordinary.

Key Responsibilities

• Facilitate effective communication with client project stakeholders regarding project status and recommendations.
• Craft client code that is efficient, performant, testable, scalable, secure, and of the highest quality.
• Actively participate in accurate planning and estimation efforts, utilizing project methods and tools.
• Proficiently gather requirements and organize/present developed features for clients.
• Execute complex activities within the current methodology and quality standards, showcasing success across diverse engagements.
• Promote client success across the team by collaborating with engineers, designers, and managers to understand user pain points, anticipate potential problems, and iterate on solutions that drive client success.
• Engage in agile software development, including daily stand-ups, sprint planning, team retrospectives, and other governance activities.
• Actively participate in the Engineering Practice community, mentoring others through Communities of Practice (CoPs) or on project teams and supporting the growth of technical capabilities.
• Independently drive project delivery within defined architecture, demonstrating autonomy and accountability in all stages from conceptualization to deployment.
• Use AI-assisted development tools (GitHub Copilot) and specification-driven practices (OpenSpec) responsibly, ensuring all AI-generated suggestions are reviewed, tested, and approved before merging or deploying.

Minimum Qualifications

UI / Frontend

• React 19 with JavaScript and JSX
• Vite for development and production builds
• Material UI (MUI), MUI Data Grid, and Emotion for components and styling
• Redux Toolkit and React Redux for shared application state
• React Context for user and feature-flag information
• React Router for client-side navigation
• Axios for communication with backend REST APIs
• Okta React and Okta Auth JS for authentication
• Vitest and React Testing Library for unit and component testing
• ESLint and Prettier for code quality and formatting
• Husky and lint-staged for pre-commit validation
• Nginx for serving the production UI

API / Backend

• Java 25
• Spring Boot 4
• Spring Web MVC for REST API development
• Spring Data JPA and Hibernate for persistence
• Microsoft SQL Server as the production database
• H2 in SQL Server compatibility mode for automated tests
• Okta OAuth 2.0 and Spring Security for authentication and authorization
• OpenAPI/Swagger for API documentation
• Gradle for builds and dependency management
• JUnit 5, Mockito, AssertJ, and Spring Boot Test for automated testing
• JaCoCo for code-coverage reporting
• Log4j2 for application logging
• Spring Boot Actuator for application health and operational endpoints
• ShedLock for controlling scheduled jobs
• Apache POI for Excel processing
• AWS SDK for S3 file storage and retrieval

Auditing and Operational Monitoring

• Spring Data JPA auditing for created-by, created-date, modified-by, and modified-date information
• Custom AOP-based user-activity auditing for important business operations
• Database-backed user-activity records
• Correlation IDs for tracking bulk-action requests
• Log4j2 application logging
• CloudWatch and OpenSearch for deployed application logs and operational analysis

Cloud and DevOps

• Docker for application packaging
• AWS ECS/Fargate for containerized deployment
• AWS ECR for Docker image storage
• AWS S3 for attachments, configuration files, and generated output files
• AWS CloudFormation for infrastructure configuration
• Harness as the primary CI/CD and deployment platform
• Snyk for dependency and container security scanning
• CloudWatch and OpenSearch for logs and monitoring
• Git and GitHub for source control, pull requests, and code reviews
• GitHub Actions for OpenSpec proposal and design automation

AI-Assisted and Specification-Driven Development

• GitHub Copilot for code suggestions, implementation, refactoring, debugging, test generation, and technical documentation
• OpenSpec for defining proposals, requirements, technical designs, implementation tasks, and acceptance criteria, keeping code changes traceable to agreed requirements
• GitHub Actions integrated with OpenSpec for automated proposal and design workflows
• Comfort reviewing, testing, and approving AI-generated suggestions before they are merged or deployed

General Qualifications

• Experience in Agile software development methodologies.
• Expertise in applying Object-Oriented Programming principles (abstraction, encapsulation).
• Experience in creating and implementing well-tested, scalable, and performant enterprise-level systems.
• Practice and initiative mentoring other engineers and decision-makers throughout the organization.
• Good understanding of SOLID principles.
• Proficiency in the English language.

Additional Experience Desired

• Experience with additional AWS services (e.g., Lambda, API Gateway) beyond the core ECS/Fargate, ECR, S3, and CloudFormation stack
• Familiarity with supplementary monitoring/observability tools (e.g., Grafana, Prometheus) alongside CloudWatch and OpenSearch
• Experience with Microsoft SQL Server backup and database maintenance tooling
• Understanding of additional authentication/authorization protocols (e.g., LDAP) alongside Okta OAuth 2.0
• Prior experience working with GitHub Copilot or similar AI pair-programming tools in a production codebase

What is it like working for 3Pillar Global?

At 3Pillar, We Offer a World Of Opportunity

• Imagine a flexible work environment - whether it's the office, your home, or a blend of both. From interviews to onboarding, we embody a remote-first approach.
• You will be part of a global team, learning from top talent around the world and across cultures, speaking English every day. Our global workforce enables our team to leverage global resources to accomplish our work in efficient and effective teams.
• We're big on your well-being - as a company, we spend a whole trimester in our annual cycle focused on well-being. Whether it is taking advantage of fitness offerings, mental health plans (country-dependent), or simply leveraging generous time off, we want all of our team members operating at their best.
• Our professional services model enables us to accelerate career growth and development opportunities - across projects, offerings, and industries.
• We are an equal opportunity employer. It goes without saying that we live by values like Intrinsic Dignity and Open Collaboration to create cutting-edge technology AND reinforce our commitment to diversity - globally and locally.