Senior Full-Stack Software Engineer

Appsierra Group; American Samoa; On-site; USD 104,000 - 208,000; Full time

Job summary

Appsierra Group is seeking a Senior Full-Stack Software Engineer for a highly experienced contract role. You will work across front-end and back-end systems on an AI training project, translating builds between languages and reviewing AI-generated code.

Responsibilities include building UI components, APIs, data models, and ensuring cross-layer integration. Strong problem-solving across systems is essential, with flexible remote scheduling.

Qualifications

• Strong professional experience building and maintaining production full-stack applications.
• Hands-on experience across both front-end and back-end engineering.
• Production experience with multiple programming languages.
• Strong knowledge of browser-based applications, APIs, state, databases, and service integrations.
• Ability to understand and contribute to the architecture of complete software systems.
• Experience working effectively within unfamiliar codebases and repositories.
• Strong debugging, analytical, and technical problem-solving skills.
• Ability to assess code quality across correctness, performance, security, and maintainability.
• Comfortable working independently in a flexible, remote environment.

Responsibilities

• Develop, modify, and debug front-end and back-end application components.
• Build and improve user-facing features along with the APIs, services, and data models that support them.
• Trace requests and data across browsers, front-end applications, APIs, services, databases, and external integrations.
• Navigate unfamiliar repositories and understand existing application architecture and implementation patterns.
• Diagnose issues involving application state, API contracts, authentication, persistence, networking, and deployment.
• Develop, review, and improve software across multiple programming languages.
• Translate complete coding implementations between programming languages while preserving functionality and behavior.
• Review AI-generated code and solutions for correctness, completeness, performance, security, and maintainability.
• Solve technically challenging software-engineering problems across different application layers.

Skills

Python

JavaScript

TypeScript

React

Node.js

Java

Rust

Go

Job description

Senior Full-Stack Software Engineer

Contract · Fully Remote · Global

Annual Compensation Equivalent: $104,000–$208,000/year
Hourly Rate: $50–$100/hour

Approximately 15 hours per week · Flexible schedule

About the Role

This contract role is for highly experienced Full-Stack Software Engineers who can work confidently across front-end and back-end systems. You’ll contribute to an AI training project involving software development, debugging, technical problem-solving, system architecture, code review, and evaluation.

The work includes creating, solving, reviewing, and validating challenging engineering tasks, as well as translating complete software builds from one programming language to another. You should be comfortable working across the full application stack rather than specializing exclusively in a single layer.

Prior AI experience is not required.

What You’ll Do

• Develop, modify, and debug front-end and back-end application components.

• Build and improve user-facing features along with the APIs, services, and data models that support them.

• Trace requests and data across browsers, front-end applications, APIs, services, databases, and external integrations.

• Navigate unfamiliar repositories and understand existing application architecture and implementation patterns.

• Diagnose issues involving application state, API contracts, authentication, persistence, networking, and deployment.

• Develop, review, and improve software across multiple programming languages.

• Translate complete coding implementations between programming languages while preserving functionality and behavior.

• Review AI-generated code and solutions for correctness, completeness, performance, security, and maintainability.

• Solve technically challenging software-engineering problems across different application layers.

Requirements

• Strong professional experience building and maintaining production full-stack applications.

• Meaningful hands-on experience across both front-end and back-end engineering.

• Production experience with multiple programming languages.

• Strong knowledge of browser-based applications, APIs, application state, databases, and service integrations.

• Ability to understand and contribute to the architecture of complete software systems.

• Experience working effectively within unfamiliar codebases and repositories.

• Strong debugging, analytical, and technical problem-solving skills.

• Ability to assess code quality across correctness, performance, security, and maintainability.

• Comfortable working independently in a flexible, remote environment.

Technical Experience

Relevant experience may include technologies such as:

• Python

• JavaScript

• TypeScript

• React

• Node.js

• Java

• Rust

• Go

Strong full-stack engineering experience is more important than expertise in every technology listed above.

Who Should Apply

This role is suited to senior software engineers who can move comfortably between the UI, application logic, APIs, services, databases, and infrastructure-related concerns.

You should be able to quickly understand unfamiliar systems, identify the root cause of technical problems, make sound implementation decisions, and evaluate solutions produced by other engineers or AI systems.

Selection Process

1. Submit an application and complete the screening questions.

2. Complete an approximately 30-minute AI interview.

3. Complete a technical assessment if required.

4. Participate in the hiring manager review.

Compensation & Engagement

• Hourly rate: $50–$100/hour

• Annual compensation equivalent: $104,000–$208,000

• Annual equivalent is calculated at 40 hours per week × 52 weeks per year and is provided for comparison; the expected engagement is approximately 15 hours per week.

• Compensation is output-based, with payment made per task that meets project specifications.

• Task completion time may vary based on experience and individual workflow.

• Minimum weekly submission requirements apply.

• Actual earnings depend on completed tasks, applicable rates, and project availability.

Schedule & Availability

• Approximately 15 hours per week

• Flexible schedule—you choose when to work, including weekends if desired, provided there is project activity.

• Roles are typically filled within approximately 48 hours.

• Selected candidates are expected to begin their first tasks within 24–48 hours after completing onboarding.