Senior Software Engineer (Fullstack)

Puzzle.io•San Francisco, CA

2d•Remote

About The Position

Accounting software hasn’t fundamentally changed in decades. The tools finance teams rely on were built for manual entry, static reports, and slow month-end workflows. We think that’s broken, and we’re fixing it. Puzzle rebuilt the accounting stack from the ground up. At the core is a real-time financial engine that ingests high volumes of data from modern fintech tools and turns it into clean, reliable financials. On top of that foundation, we’re building the workflows, automation, and insights that help accounting professionals move faster, without sacrificing accuracy. We move quickly. We ship often. And we don’t compromise on correctness. We’re looking for a Senior Software Engineer who can take ownership of meaningful product areas, collaborate tightly with stakeholders, and execute with both speed and care. The Opportunity This is a fast-paced startup. Priorities evolve. Scope sharpens as we learn. Engineers are expected to participate in shaping solutions- not just implementing tickets. Velocity matters here. But so does trust. Our customers rely on our systems for financial accuracy. That means clean abstractions, thoughtful data handling, and strong engineering judgment. We build for clarity, performance, and maintainability- not shortcuts. We also believe AI-assisted development is table stakes. We want engineers who actively leverage AI tools to increase productivity, explore edge cases, and improve code quality, without outsourcing thinking. If you thrive in high-ownership environments, care deeply about building correct and maintainable systems, and want to move fast while solving real, meaningful problems- this is the role for you.

Requirements

5+ years building production software in fast-moving environments
Comfortable working across a modern web stack, including React, TypeScript, Next.js, and Node
Experience designing, building, and consuming APIs (REST, GraphQL)
Strong understanding of relational databases and data modeling
Experience collaborating closely with Product Managers on iterative product development
High agency- you take ambiguous problems and turn them into shipped solutions
Good judgment- you know when to move fast and when to slow down
Care deeply about code quality, maintainability, and long-term system integrity
Thrive in startup environments where ownership is high and process is lightweight
Actively use AI to improve your workflow and output

Nice To Haves

Experience in fintech, accounting systems, or other correctness-critical domains.

Responsibilities

Own product features end-to-end, from scoping through shipping and iteration
Partner closely with Product Managers to clarify ambiguous requirements and make smart tradeoffs
Build scalable, maintainable systems across the stack
Ship customer-facing value quickly without compromising correctness
Improve performance, reliability, and developer experience across the codebase
Contribute to architectural decisions that unlock future scale
Raise the bar through thoughtful code reviews and strong engineering standards
Take initiative - identifying problems and driving solutions without waiting for direction