Senior Ai-Native Engineer: Codebase & Harness Reviewer

Terac; La Pampa; Remote; ARS 138,361,000 - 230,602,000; Full time

Benefits offered by this job

Contractor payment in USD

Remote work

Argentina holidays

English classes

Referral program

Learning platforms

Job summary

Darwoft is seeking a Senior / Staff Software Engineer to architect and build production software in an AI-native environment. You’ll navigate a large codebase, design features, and drive architectural decisions while leveraging Claude Code, Codex, and other AI tools to accelerate delivery.

You’ll mentor and collaborate with a small team, improve tooling, and ensure reliability across multi-location deployments. Fully remote from LATAM, contractor vibe with USD pay.

Qualifications

• Strong professional experience building and operating production software systems.
• Excellent software engineering fundamentals including architecture, system design, debugging, testing, and maintainability.
• Experience with large or complex existing codebases.
• Backend or full-stack engineering experience using modern languages and frameworks.
• Experience building modern web applications and SaaS products.
• Strong understanding of APIs, architecture, integrations, data modeling, and distributed systems.
• Experience with relational databases and production data environments.
• Strong understanding of automated testing and modern software development practices.
• Familiarity with cloud environments, CI/CD pipelines, deployments, and production operations.
• Ability to reason through technical trade-offs and make pragmatic architectural decisions.
• Strong ownership and ability to work independently in an evolving product environment.
• Product mindset: understanding not only how to build but why it should be built.

Responsibilities

• Navigate, understand, and evolve a large existing production codebase.
• Design and implement new product capabilities across a complex SaaS platform.
• Make pragmatic architectural and system design decisions as the product scales.
• Identify technical debt, architectural risks, reliability issues, and opportunities for improvement.
• Use Claude Code, Codex, Cursor, Copilot, or similar AI coding agents extensively.
• Leverage AI agents to explore codebases, design implementations, generate and refactor code, and accelerate delivery.
• Build and evolve backend services, APIs, data models, and application workflows.
• Contribute across the application stack when needed.
• Strengthen automated testing, observability, reliability, and production readiness.
• Improve development workflows, tooling, automation, and engineering practices.
• Troubleshoot complex issues across application, data, and infrastructure layers.
• Balance development speed with software quality and long-term maintainability.
• Work with product leadership to translate problems into technical solutions.
• Help the team achieve greater development leverage through AI-assisted engineering.

Skills

Production software

Architecture

System design

Debugging

Testing

Maintainability

Large codebases

Backend / Full-stack

Web apps

APIs

Distributed systems

Data modeling

Integrations

Relational DBs

Automated testing

Cloud

CI/CD

Deployments

Production ops

Architectural decisions

Ownership

Independent work

Product mindset

Tools

Claude Code

OpenAI Codex

AI coding agents

Job description

Our client is a digital marketing agency that helps multi-location businesses with a physical presence turn strong in-person operations into online revenue. Its clients include med spas and aesthetics practices, clinics, OB/GYN practices, senior living communities, and dispensaries across the US and Canada. They usually have good operations and good reviews, and little online presence.

The agency is AI-native. It runs on Claude and on its own internal operating system and client portal. Anything digital is in scope, from search, SEO, and visibility in AI answers to websites, booking paths, reviews, social, paid media, branding, and fractional CMO support.

Your Role

This is a hands-on account manager role. You own a set of client accounts end to end, from the first proposal through onboarding and the months after. You write the brand messaging and copy yourself, drafting in Claude and editing until it sounds like the client, and you run SEO, social, and paid media directly, including conversion tracking and ad account structure.

Part of the job is building. You'll convert repeated tasks into Claude tools and workflows (briefs, content calendars, trackers) and improve how the team works. Clients in med spas and senior living are particular about tone and trust, so every AI draft gets edited and checked before a client sees it.

This role suits someone who wants the whole account rather than a single channel, and who's comfortable building parts of the process as they go. If you'd prefer to hand execution to a team once the plan is written, it probably isn't the right fit.

You'll

Onboard new accounts and get the site, tracking, and channels live in about two weeks

Confirm conversion tracking counts real bookings before budget moves

Write brand messaging, location pages, and client updates, drafted in Claude and edited by you

Run SEO, social, and paid media hands-on, including ad account structure

Structure multi-location accounts so each location's numbers read clearly, then compare cost per booked appointment and shift budget

Convert repeated tasks into Claude workflows the team uses every week

Join client calls, including some in other time zones

You Bring

• 5+ years of current, hands-on digital marketing for clients, at an agency or your own practice
• Technical grounding in conversion tracking, tags, ad account structure, or launching sites
• Daily use of Claude and the tools that connect to it, plus something you've built with them
• Near-native English for client calls and written updates
• Experience running several client accounts at once, often with multiple locations
• Brand and copy judgment you can explain and defend
• Comfort working with minimal oversight

Bonus Points

• A strong portfolio of client work
• Published work or a personal brand, such as a course or newsletter
• Clients in aesthetics, healthcare, senior care, or regulated retail
• A technical degree in computer science, BI, or data analytics

What's Offered

• Fully remote, full-time contractor role from LATAM
• Working hours on US Central time, with some flexibility for client calls in other time zones
• Paid in USD as a contractor. Share the range that fits your level and we'll go from there
• Unlimited PTO, and you choose which holidays you observe
• Scope and responsibility that grow as the agency grows

Interview Process

1. First Call: A 30-minute conversation with atomic HR
2. First Team Interview: Your first interview with the team
3. Second Team Interview: A second interview with the team
4. Work Test: A short practical task
5. Final Interview: The last conversation before a decision
6. Offer: An offer if it's a match on both sides

Senior/Staff Software Engineer (AI-Native/Claude Code/Codex) · LATAM

• Location: Anywhere in LATAM
• Job Type: 100% Remote
• Engagement: Full-time Contractor
• Payment: USD
• Project: AI-Native LegalTech / M&A SaaS Platform
• Seniority: Senior / Staff
• English Level: B2 / C1

Get to Know Darwoft

At Darwoft, we build digital products with heart. We're a Latin American technology company focused on creating impactful, human-centered software in partnership with companies around the globe.

Our remote-first culture is built on trust, continuous learning, collaboration, and strong engineering standards. We work with international teams solving complex product and technology challenges where our engineers can have a direct impact on the product.

If you're looking for a place where your technical judgment matters and where you can contribute beyond simply executing tickets, welcome to Darwoft.

About the Opportunity

We're partnering with an innovative software company building a modern transaction platform for organizations managing complex M&A processes.

The platform brings together document workflows, collaboration, approvals, diligence, transaction management, and AI-powered capabilities within a single SaaS product.

What makes this opportunity particularly different is the way the engineering team builds software.

The product has been developed using an AI-native engineering approach , with tools such as Claude Code, OpenAI Codex, and other AI coding agents deeply integrated into the development workflow.

We're looking for a highly experienced Senior / Staff Software Engineer who can combine strong software engineering fundamentals with this new way of building software.

This is not a traditional AI/ML Engineer role .

You won't be training machine learning models or working primarily on Data Science. Instead, you'll be engineering production software, navigating a large existing codebase, making architectural decisions, improving reliability, and using AI coding agents to dramatically increase development velocity.

The ideal person is a builder first : highly technical, pragmatic, product-oriented, low-ego, and comfortable taking ownership of complex systems.

What You'll Be Doing

• Navigate, understand, and evolve a large existing production codebase.
• Design and implement new product capabilities across a complex SaaS platform.
• Make pragmatic architectural and system design decisions as the product continues to scale.
• Identify technical debt, architectural risks, reliability issues, and opportunities for improvement.
• Use Claude Code, Codex, Cursor, Copilot, or similar AI coding agents extensively throughout the software development lifecycle.
• Leverage AI agents to explore codebases, design implementations, generate and refactor code, debug issues, write tests, and accelerate delivery.
• Build and evolve backend services, APIs, integrations, data models, and application workflows.
• Contribute across the application stack when needed.
• Strengthen automated testing, maintainability, observability, reliability, and production readiness.
• Improve development workflows, tooling, automation, and engineering practices.
• Troubleshoot complex issues across application, data, and infrastructure layers.
• Balance development speed with software quality and long-term maintainability.
• Work closely with product leadership to translate business problems into effective technical solutions.
• Help a small engineering team achieve significantly greater development leverage through AI-assisted engineering.

What You Bring

• Strong professional experience building and operating production software systems .
• Excellent software engineering fundamentals, including architecture, system design, debugging, testing, and maintainability .
• Experience working with large or complex existing codebases .
• Strong backend or full-stack engineering experience using modern programming languages and frameworks.
• Experience building modern web applications and SaaS products .
• Strong understanding of APIs, application architecture, integrations, data modeling, and distributed systems .
• Experience with relational databases and production data environments.
• Strong understanding of automated testing and modern software development practices.
• Familiarity with cloud environments, CI/CD pipelines, deployments, and production operations.
• Ability to reason through technical trade-offs and make pragmatic architectural decisions.
• Strong ownership and ability to work independently in an evolving product environment.
• Product mindset: you understand not only how to build something, but also why it should be built.

Nice to Have

• Experience working in early-stage or high-growth product companies .
• Previous experience as a Staff Engineer, Principal Engineer, Tech Lead, Founding Engineer, or similar high-ownership role .
• Experience building AI-powered SaaS products.
• Experience integrating LLMs or AI APIs into production applications.
• Experience with document-heavy or workflow-intensive platforms. There seems a missing closing tag. Let's just keep as proper.
• Experience designing authorization systems, permissions, RBAC, and auditability.
• Experience with LegalTech, FinTech, transaction platforms, Private Equity, or other complex B2B SaaS products.
• Experience improving engineering productivity through developer tooling and automation.

What Success Looks Like

Success in this role goes beyond writing more code.

You’ll help the team ship significantly faster while simultaneously strengthening the architecture, reliability, maintainability, and technical maturity of the platform .

The goal is to combine strong engineering judgment with AI-native development practices to dramatically increase what a small engineering team can build.

What Darwoft Offers

• Contractor agreement with payment in USD
• 100% remote work
• Argentina's public holidays
• English classes
• Referral program
• Access to learning platforms

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