Principal Engineer
Fluxx
Tailor my CV for this job, freeView job and applyYour CV rewritten for this role, from your real experience. Sign in with Google, nothing to install.
Got this interview? Our apps help you get the job.
Skills named in this job
Read from the description itself, not inferred.
This role on the market
AWS jobs · Elasticsearch jobs · Go jobs · Java jobs
Counted across 14 company job boards, updated as roles open and close.
Preparing for this interview
Practise the questions Fluxx is likely to ask for this role, with feedback on your answers.
Questions you are likely to be asked
- Why do you want to join Fluxx?
- What is your experience with Node.js? Tell me one thing you learned the hard way.
- How would you design an API for a feature you have worked on?
- What do you do when a production issue happens on your code?
- Walk me through a system you built. How was it designed, and what would you change now?
Prep Sarthi gives you a free mock interview: an AI interviewer asks you questions like these out loud, from your own CV and this job, and shows your score and your weakest answer.
Practise the Principal Engineer at Fluxx interview free →Fluxx is looking for a highly motivated Principal Engineer to join the Engineering team. As a Principal Engineer at Fluxx, you'll be a senior technical leader on our engineering team, responsible for driving the architecture and implementation of large, cross-cutting initiatives on our grantmaking platform. You will work closely with our SVP of Engineering, our co-founding CTO, Director of Engineering, fellow Principal Engineers, and our product and infrastructure teams to make the right architectural calls, write meaningful code, and help the broader team raise its technical bar. This is a hands-on role. You'll spend the majority of your time in code, working through real problems and deliverables end-to-end, and the rest of your time on design, technical direction, and unblocking others. We are looking for someone who considers alternatives carefully, weighs trade-offs against the realities of our system, and is comfortable putting their opinions on the table and being challenged on them. This is a full-time exempt and remote position. Candidates must be located in the United States. **How you will make an impact:** * Lead the architecture and implementation of major initiatives in our platform * Make architectural decisions counterfactually - considering several plausible approaches, surfacing the trade-offs, and choosing the best path rather than defaulting to a generic template * Provide technical leadership across all phases of large-scale engineering work, from scoping and design through implementation, code review, rollout and maintenance * Work cross-functionally with the Director of Engineering, fellow principal engineers, infrastructure engineers, product managers, DevOps, and QA to drive complex decisions on product direction and process improvements * Design and implement user-facing and backend features across the entire platform * Produce high-quality code that is well designed, thoroughly tested, and passes peer review * Lead and drive best practices with the team across the entire SDLC * Mentor engineers across the team, raise the architectural literacy of the group, and actively contribute to brainstorming and design discussions * Represent the engineering organization in leadership discussions and occasionally in direct conversations with customers. * Champion thoughtful use of AI and agents in our SDLC, helping the team amplify their work **What you bring to the team:** * 8+ years of professional software engineering experience, with a meaningful share of that as a principal engineer or architect on a complex SaaS platform * Deep experience as a full-stack engineer, with substantial depth using NodeJS and React * A habit of considering alternatives, naming the trade-offs, and choosing the right path for the system in front of you rather than reaching for a textbook answer * Confidence to put your opinion on the table, ask the questions others aren't asking, and engage in brainstorming and architectural debate * Strong written and verbal communication, with experience working closely with product, design, QA, and infrastructure peers * A deep foundation in computer science and a track record of making web applications highly performant * Dedication to writing and maintaining documentation that helps others move faster * Willingness to adapt to a fast-paced environment, to a codebase with a long history, and to a rapidly evolving AI-assisted development model * A track record of mentorship and of raising the technical bar of the engineers around you * Proven ability to navigate complex technical trade-offs, ensuring rapid feature delivery without compromising long-term platform scalability **Technical Experience:** * Node.js, React and modern JavaScript/TypeScript * Large Ruby on Rails codebases - you should be able to speak credibly across both ecosystems * AWS and DevOps fundamentals - you do not need to be an infrastructure specialist, but you should be comfortable reasoning about deployment, scaling, and observability * MySQL at scale, including query optimization, indexing strategies, and schema migrations on live systems * Elasticsearch, Redis, Resque, and other supporting services in a production Rails environment * AI-assisted development workflows, including thoughtful use of agents, prompt design, and the operational realities of keeping agentic SDLC pipelines healthy * B2B SaaS platforms, particularly those with highly configurable customer-specific behavior * Bonus points if you have some experience with Go, Python and other modern languages used in systems targeting high-performance and concurrency features, and Java * **Salary:** Fluxx is committed to fair, transparent, and equitable compensation practices. We use a market based approach that considers cost of labor by geographic region, along with company size and industry benchmarks. This role is categorized into two compensation zones based on location, with the following expected annual base salary: * Zone 1 – San Francisco Bay Area & New York City $164,000- $210,000 * Zone 2 – All other locations $147,600- $199,800 The range listed reflects the expectations outlined in this job description. The final salary and commission package will be determined based on, but not limited to: (a) the candidate’s location, (b) individual skills and qualifications, and (c) relevant experience. **Benefits:** Fluxx offers the following benefits for the position subject to applicable eligibility requirements: Medical, dental, and vision insurance; Flexible time off; Paid sick leave; 12 weeks of fully-paid parental leave; Annual learning and development stipend; Internet stipend; One-time home office set-up stipend; 401(k) retirement plan with company match. This position is also eligible for incentive stock options, subject to the terms of Fluxx’s applicable stock plans. **About Fluxx: ** At Fluxx, our mission is to be the leading collaborative grant management platform in our global communities. We build technology that drives positive impact by helping foundations, government agencies, and nonprofits streamline the grantmaking process—making it easier to get funding to the organizations that need it most. For more than 15 years, we’ve helped organizations move away from manual processes and legacy tools to a flexible, AI + data-driven platform that supports the full lifecycle of grantmaking. Today, Fluxx supports a global community of 400+ customers who collectively manage and distribute more than $39B in grants annually. We are a people-first and inclusive workplace committed to continuous learning. We pride ourselves on having a diverse workforce and we do not discriminate against any employee or applicant because of race, creed, color, religion, gender, sexual orientation, gender identity/expression, national origin, disability, age, genetic information, veteran status, marital status, pregnancy or related condition, or any other basis protected by law. We respect the gender, gender identity and gender expression of our applicants and employees. It is our policy to comply with all applicable national, state and local laws pertaining to nondiscrimination and equal opportunity.
Match this job to your CV
ApplySarthi scores your CV against this role, shows the skills you are missing, and writes a tailored version for the application.
Check my match →Similar open roles
- Principal EngineerTwilio
- Principal EngineerGraphcore
- Principal EngineerRaft Company Website
- Principal EngineerRaft Company Website
- Principal EngineerThe AI Whistleblower Initiative
- Principal EngineerNagarro
- Principal EngineerNagarro
- Principal EngineerNagarro
Need answers during your interview? Try Live Sarthi.
Live Sarthi, an Interview Sarthi app, shows answer suggestions during the call.
- Hidden from supported screen sharingThe overlay stays out of supported Windows screen captures.
- Answers start in about 1.5 secondsResponse time varies with your connection and model.
- From your own CVYour projects and your experience, not a generic script.
- 30 minutes freeThen ₹99 for a 2-day pass with unlimited calls — you pay for the days you are interviewing, not a subscription.
A Windows app, from the same team as ApplySarthi.
Listed on wellfound · posted 2026-08-28. ApplySarthi collects openings and links to application pages; the role is advertised by Fluxx, not by us.