Software Development Engineer, Fees Tech.

Are you an SDE II who thrives on end-to-end ownership, gets energized by problems where correctness actually matters, and wants to work on systems that are actively being reimagined and not just maintained? This role might be for you.
On Fee Tech, you will own systems that 2+MM sellers depend on daily to understand, predict, and act on their economics. The work is genuinely end-to-end: you design, build, ship, and operate. Our systems process ~68.5B transactions and used across 23 countries. The engineering model is changing fast: we are rebuilding how fee policy is expressed, deployed, and validated using AI agents, formal verification (SMT), and self-improving RL loops.

You will work alongside senior and principal engineers, product managers, applied scientists, and ML engineers across the full fee lifecycle — from the Fee Calculation Engine through ML-based item classification to seller-facing AI surfaces and the agentic infrastructure beneath them. If you are the kind of engineer who wants to see the direct impact of what you ship, you will see it here.

Key job responsibilities
- Design and build distributed systems.
- Deliver features end-to-end: own requirements scoping, technical design, implementation, code review, testing, launch, and operational monitoring for your workstreams — from initial design doc through production.
- Operate AI-native engineering practices: use AI-assisted coding, multi-agent workflows, and agentic code review tools as your default mode of software delivery.
- Build and maintain agentic systems with a focus on correctness, latency, and self-improvement loops.
- Drive operational excellence: participate in oncall rotation, resolve incidents, reduce MTTR, contribute to postmortems and preventive action items, and build tooling that reduces KTLO burden for the team.
- Collaborate across disciplines: partner with product managers defining seller experience roadmaps, UX designers shaping how sellers interact with fee surfaces, data and applied scientists building ML models for fee classification and seller economics analysis, and business stakeholders across WW Global Selling, FBA, and Finance.
- Contribute to technical strategy: write design documents and architecture proposals that are reviewed and challenged by senior engineers; participate actively in architectural discussions around the three-year Agentic Architecture Plan.
Mentor and support peers: review code with a high bar, share feedback constructively, and help junior engineers grow through pairing, design reviews, and documentation.

Basic Qualifications:
- 3+ years of non-internship professional software development experience
- 1+ years of designing and developing large-scale, multi-tiered, multi-threaded, embedded or distributed software applications, tools, systems, and services using: C#, C++, Java, or Perl experience
- Bachelor's degree or foreign equivalent in Computer Science, Engineering, Mathematics, or a related field
- Experience programming with at least one software programming language

Preferred Qualifications:
- Master's degree in computer science or equivalent
- Experience with Machine Learning and Large Language Model fundamentals, including architecture, training/inference lifecycles, and optimization of model execution, or experience in computer architecture

Amazon is an equal opportunity employer and does not discriminate on the basis of protected veteran status, disability, or other legally protected status.

Our inclusive culture empowers Amazonians to deliver the best results for our customers. If you have a disability and need a workplace accommodation or adjustment during the application and hiring process, including support for the interview or onboarding process, please visit https://amazon.jobs/content/en/how-we-hire/accommodations for more information. If the country/region you’re applying in isn’t listed, please contact your Recruiting Partner.

The base salary range for this position is listed below. Your Amazon package will include sign-on payments and restricted stock units (RSUs). Final compensation will be determined based on factors including experience, qualifications, and location. Amazon also offers comprehensive benefits including health insurance (medical, dental, vision, prescription, Basic Life & AD&D insurance and option for Supplemental life plans, EAP, Mental Health Support, Medical Advice Line, Flexible Spending Accounts, Adoption and Surrogacy Reimbursement coverage), 401(k) matching, paid time off, and parental leave. Learn more about our benefits at https://amazon.jobs/en/benefits.

USA, WA, Seattle - 143,700.00 - 194,400.00 USD annually