Senior Product Engineer

Fine Tune; United States; Remote; USD 130,000 - 160,000; Full time

Job summary

Fine Tune is seeking a Senior Product Engineer to own problems end to end, from ambiguous ideas to shipped solutions. You’ll partner with AI coding agents to shape specs, review outputs, and ensure design quality across Rails/JavaScript stacks.

Remote in the United States with a focus on procurement and finance domains. You will mentor engineers, drive architectural decisions, and collaborate with product and QA to deliver iterative, robust features.

Qualifications

• 5+ years of professional product or software engineering experience.
• Strong proficiency in Ruby and JavaScript/TypeScript with full‑stack frameworks.
• Independently produces clean, tested implementations and debugs complex issues.

Responsibilities

• Own projects from problem definition through delivery and ongoing maintenance.
• Design systems within our architecture with clear boundaries and interfaces.
• Build AI‑driven solutions and review AI‑generated code for correctness.
• Verify behavior against intent and apply security practices.
• Mentor engineers and provide thoughtful code reviews.
• Collaborate with product and QA to turn business needs into scoped work.

Skills

Product/software engineering

Ruby

JavaScript/TypeScript

Full-stack frameworks

AI coding tools

Problem ownership

Software design

Debugging complex issues

Tools

Git

CI/CD pipelines

Infrastructure as code

Hotwire/Stimulus

Cloud platforms

Docker

AI coding tools (Claude Code, Cursor, Copilot)

Job description

We’re looking for a Senior Product Engineer who owns problems end to end — from an ambiguous idea through a shipped, maintained solution — and lifts the engineers around them while doing it. You’ll join a collaborative team building the platforms that help some of the world’s largest companies manage complex indirect spend.

We build with AI at the center of our workflow. You’ll work alongside AI coding agents every day: shaping problems and writing specs and plans they can execute against, then reviewing and verifying what they produce. The judgment you bring to design, scope, and correctness matters more here, not less.

You’ll also be expected to learn our business deeply. Our clients are procurement and finance teams at major global companies, and the best decisions here come from understanding why their world works the way it does.

At Fine Tune, our core values of honesty, dedication, and vigilance foster an environment of trust, open communication, and inclusivity where everyone can do their best work. If you care about your craft, want to keep getting better, and thrive in a team that’s building something meaningful — let’s talk.

This is a full-time, salaried, remote position. Candidates must be US citizens and located in the United States.

Responsibilities and Duties

• Own Problems & Deliver:
  • Own projects from problem definition through delivery and ongoing maintenance, including problems that start ambiguous or loosely defined
  • Compare viable approaches and recommend one with clear reasoning
  • Cut scope to fit the time available, and know when to cut and when to elevate
  • Produce clean, well‑tested implementations across Rails and JavaScript/TypeScript; design data models and APIs other engineers build on
• Design & Decide:
  • Design systems within our architecture — decompose problems into components with clear responsibilities, boundaries, and interfaces
  • Design for failure as well as for the happy path
  • Weigh tradeoffs and make the reasoning behind consequential decisions clear
  • Debug complex, cross‑cutting issues systematically and get to root cause
• Build AI:
  • Use AI coding agents as a core part of how you deliver: decompose work into well‑defined specs and plans, direct implementation, and iterate on the results
  • Own every line that ships, whoever or whatever wrote it. Understand it well enough to explain it, predict its behavior, and change it
  • Review AI‑generated code with deliberate thoroughness for correctness, security, and fit with our architecture
  • Help improve our AI development workflow, including the context, conventions, and automated gates that make agent output reliable
• Verify & Protect:
  • Choose the right verification strategy for the work and verify behavior against intent, not just against the implementation
  • Apply established security patterns and handle sensitive client data appropriately
  • Spot security risk before it ships
• Mentor engineers; give thoughtful code reviews that raise the team’s bar by example with well designed and scalable architecture
• Evaluate implementations you didn’t write for correctness, security, and fit
• Drive technical decisions and build consensus across the team without relying on authority
• Identify and lead improvements to code, architecture, testing, and process
• Partner with product and QA to turn business needs into well‑scoped work delivered iteratively
• Work in fixed cycles with a small team that owns shaped work end to end
• Communicate decisions, tradeoffs, progress, and risks clearly across the team
• Contribute to architecture and design discussions and to team learning initiatives like book clubs and mentoring

What We’re Looking For

• Craft
  • 5+ years of professional product or software engineering experience, or equivalent demonstrated ability
  • Strong proficiency in modern web development languages (Ruby and JavaScript/TypeScript preferred) and full‑stack frameworks (Rails, React, or similar)
  • Independently produces clean, tested implementations and debugs complex issues systematically
  • Designs systems within an existing architecture and applies patterns appropriately
  • Designs efficient data models, optimizes queries and indexes, and implements security measures
  • Comfortable with Git, CI/CD pipelines, infrastructure as code, and modern development tooling
  • Hands‑on experience building production software with AI coding tools (Claude Code, Cursor, Copilot, or similar), and a clear point of view on where they help, where they don’t, and how you verify their output
  • Demonstrated ability to own a project end to end, from problem definition to production
• Domain
  • Deep understanding of the business your software serves, or a clear track record of building that understanding quickly
  • Comfortable reasoning about the why behind a requirement, not just the what
• Professional Skills
  • Strong communicator — you present complex technical information clearly and facilitate productive discussions
  • Collaborative and empathetic — you drive cross‑team collaboration and build strong working relationships
  • Creative problem solver — you solve novel problems and make sound decisions with incomplete information
  • Ownership mindset — you take ownership beyond your immediate role and drive initiatives to completion
  • A leader without authority — you influence significant technical decisions and mentor others as they grow
  • Organized and adaptable — you balance priorities, estimate accurately, and adapt as requirements change

Nice to Have

• Experience with Ruby on Rails specifically, including Hotwire and Stimulus
• Familiarity with cloud platforms and managed platforms (Railway, Heroku, Azure, AWS, or comparable) and containerization (Docker)
• Microsoft integrations (Entra, Dynamics 365, SharePoint)
• Understanding of API design (REST, GraphQL) and architectural patterns
• Exposure to enterprise software, procurement, or expense management domains

Why Join

Growth Path: We invest in your development with clear career progression, regular feedback cycles, and a rubric‑based framework so you always know where you stand and where you’re headed

Learning Culture: Book clubs, mentoring programs, and a team that values continuous improvement — we believe in “Learn One, Do One, Teach One”

AI‑Native Engineering: We’ve rebuilt how our team works around AI‑assisted development, with real investment in the workflow, tooling, and guardrails, so you’ll spend your time on the parts of the job that need an engineer

Collaborative Team: Work with a tight‑knit engineering team that values quality, open communication, and professional growth in an inclusive environment

Meaningful Impact: Your work directly helps remove the tedious, complex work that bogs down procurement and finance teams at major global companies

Healthy Balance: Remote flexibility with respect for work‑life balance — we believe sustainable work leads to better outcomes

The pay range for this role is: 130,000 – 160,000 USD per year (Remote (United States))

Fine Tune’s cost reduction consultants help clients optimize their most complex and burdensome indirect services, delivering lasting P&L impact and sustainable solutions.