Sr Javascript Developer

Sonatafy Technology | Software Delivery Done Right; United States; Remote; USD 140,000 - 210,000; Full time

Job summary

Sonatafy Technology, the nearshore software development and staff augmentation partner, is seeking a Senior Backend Engineer to join the client’s hypergrowth team. You’ll own and mentor backend systems, shaping the technical direction and delivering high-throughput, maintainable services.

You’ll lead a team, define architectural patterns, ensure performance, security, and reliability while collaborating with frontend and cross-functional peers.

Qualifications

• 8+ years of professional backend engineering experience in high-throughput, high-availability environments.
• 5+ years of NodeJS experience and 6+ years with MongoDB (indexes, aggregations, replica sets, sharding).
• Strong AWS experience (EC2, ECS, S3, Lambda, CloudWatch) and containerization with Docker.
• Knowledge of DNS, VPNs, networking, firewalls, and auto-scaling for reliable services.
• Excellent leadership, mentoring abilities, and ability to drive technical decisions.

Responsibilities

• Lead and mentor a team of engineers, fostering a collaborative and high-performing environment.
• Propose and implement scalable architectural patterns to support growth and maintainability.
• Define and enforce coding standards and architectural guidelines.
• Follow and contribute to existing software design patterns.
• Identify and resolve data/process bottlenecks.
• Maintain and update the codebase.
• Collaborate with the Frontend team to ensure performant features.
• Conduct code reviews and provide constructive feedback.
• Troubleshoot and resolve complex technical issues.

Skills

Backend leadership

NodeJS

MongoDB

AWS

Docker

Networking

AI experience

Code reviews

Tools

DNS

VPNs

Job description

Sonatafy Technology, the exceptional nearshore software development and staff augmentation company, is partnering with a rapidly expanding startup. We're on the hunt for a talented Senior Backend Engineer to join their crew and contribute to their, dare we say, groundbreaking platform. If you're tired of the same old code and crave a place where your ideas actually matter, this might be your gig.

About the Project:

You'll be embedded within our client's team, a dynamic company experiencing hypergrowth. You'll be a key player in developing their core applications, working alongside and leading a team of engineers who are passionate about their work. This is a chance to make a real impact, shape the technical direction, and be part of a company that's disrupting its industry.

Responsibilities:

• Lead and mentor a team of engineers, fostering a collaborative and high-performing environment.
• Propose and implement scalable architectural patterns to support the application's growth and ensure long-term maintainability.
• Define and enforce coding standards, best practices, and architectural guidelines.
• Follow and contribute to existing software design patterns.
• Identify and resolve data/process bottlenecks.
• Maintain and update the codebase.
• Collaborate with the Frontend team to ensure new features are performant and meet design requirements.
• Conduct code reviews and provide constructive feedback.
• Troubleshoot and resolve complex technical issues.

Requirements and Skills:

• Proven experience working on high-throughput, high-availability applications, with experience in a lead role.
• 8+ years of professional backend engineering experience.
• 5+ years of experience with NodeJS.
• 6+ years of experience with MongoDB (specifically with Indexes, Aggregation Pipelines, Replica Sets, and Sharding).
• Strong systems operations experience with AWS services (EC2, ECS, S3, Lambda, Rekognition, Elasticache, AmazonMQ, CloudWatch).
• Experience with Docker and container orchestration.
• Demonstrated experience with DNS, VPNs, Networking, Firewalls, static asset delivery, application load balancing, and auto-scaling.
• (Preferred) Experience working with AI.
• Strong understanding of web design best practices, standards, and modern web application development trends.
• Excellent communication and leadership skills, with the ability to mentor and guide team members.
• Proven ability to make sound technical decisions and drive projects to completion.
• Experience in technical planning and roadmap development.

Why Work with Sonatafy?

At Sonatafy, you'll join a community of highly skilled engineers across Latin America supporting innovative U.S.-based teams. You’ll be part of a fast-moving, client-first culture where your code has real-world impact. We offer competitive compensation, a remote-first lifestyle, and career growth opportunities across industries and technologies.