Principal Engineer

Fluxx

3d•$147,600 - $225,000•Remote

About The Position

Fluxx is seeking a highly motivated Principal Engineer to join its Engineering team. This is a hands-on senior technical leadership role focused on driving architecture and implementation for major, cross-cutting initiatives on Fluxx’s grantmaking platform. The position works closely with engineering leadership, other Principal Engineers, product, and infrastructure teams to make architectural decisions, deliver code, and raise the team’s technical standards. Most of the role is spent writing code and delivering work end-to-end, with the remaining time dedicated to design, technical direction, and unblocking others. The successful candidate will carefully weigh alternatives and trade-offs in the context of Fluxx’s systems, and be comfortable sharing and defending technical opinions while engaging in debate. This is a full-time, exempt, remote position. Candidates must be located in the United States. Contractors are not being accepted. The role’s annual base salary range is $164,000–$225,000 in Zone 1 (San Francisco Bay Area and New York City) and $147,600–$214,100 in Zone 2 (all other locations). Final compensation depends on location, skills, qualifications, and relevant experience. The position is eligible for incentive stock options, subject to applicable plan terms. Fluxx builds a collaborative grant management platform used by foundations, government agencies, and nonprofits. The company describes itself as a people-first and inclusive workplace committed to continuous learning and equal opportunity.

Requirements

At least 8 years of professional software engineering experience, with a meaningful portion as a Principal Engineer or architect on a complex SaaS platform.
Deep full-stack engineering experience, including substantial experience with Node.js and React.
Ability to assess alternatives, explain trade-offs, and select an approach appropriate to the system rather than defaulting to generic patterns.
Confidence sharing opinions, raising questions, and participating in brainstorming and architectural debate.
Strong written and verbal communication skills, including experience working closely with product, design, QA, and infrastructure colleagues.
Strong computer science foundation and a track record of improving web application performance.
Dedication to writing and maintaining documentation that helps others work effectively.
Ability to adapt to a fast-paced environment, a long-standing codebase, and evolving AI-assisted development practices.
A record of mentoring and raising the technical standards of other engineers.
Ability to navigate complex technical trade-offs while supporting feature delivery and long-term platform scalability.
Experience with Node.js, React, and modern JavaScript/TypeScript.
Ability to work credibly across large Ruby on Rails codebases and the Node.js/React ecosystem.
Familiarity with AWS and DevOps fundamentals, including deployment, scaling, and observability.
Experience with MySQL at scale, including query optimization, indexing, and live-system schema migrations.
Experience with Elasticsearch, Redis, Resque, and supporting services in a production Rails environment.
Experience with AI-assisted development workflows, including agents, prompt design, and maintaining healthy agentic SDLC pipelines.
Experience with B2B SaaS platforms, particularly platforms with highly configurable, customer-specific behavior.

Nice To Haves

Experience with Go, Python, or other modern languages used for high-performance and concurrency-focused systems.
Experience with Java.

Responsibilities

Lead the architecture and implementation of major initiatives on the platform.
Evaluate multiple plausible architectural approaches, surface trade-offs, and choose a path suited to the system.
Provide technical leadership through the full lifecycle of large-scale engineering work, including scoping, design, implementation, code review, rollout, and maintenance.
Collaborate with engineering leadership, Principal Engineers, infrastructure, product management, DevOps, and QA on complex product and process decisions.
Design and implement user-facing and backend features across the platform.
Write high-quality, well-designed, thoroughly tested code and participate in peer review.
Lead and promote best practices across the software development lifecycle.
Mentor engineers, improve the team’s architectural literacy, and contribute to brainstorming and design discussions.
Represent Engineering in leadership discussions and, occasionally, in direct customer conversations.
Promote thoughtful use of AI and agents in the software development lifecycle.