Principal Software Engineer

Company Overview At Fluency, we come together under two shared passions that drive our culture: the scaling of digital ad operations, and fostering a workplace environment rooted in open communication, inclusivity, and a growth-oriented mindset. These passions not only set us apart in the industry, but also fuel our collective drive to reshape the industry and reinvent ourselves along the way. We're not just revolutionizing the digital advertising horizon, we're shaping an organization where every member feels a sense of pride and is inspired to do their best work. Team Overview The Fluency Engineering Team is detail-oriented and extraordinarily passionate about digital advertising. We blend the art and science of advertising into simple and scalable solutions to complex problems, and deliver leading-edge software products to our customers. Our culture is rooted in open communication, inclusivity, and a growth-oriented mindset as we reshape the digital advertising horizon. Fluency operates at the scale of $3B+ in annualized media spend across more than 250,000 campaigns per month. The DSP Integrations team is responsible for the technical relationship between Fluency's automation platform and the major Demand-Side Platforms we integrate with: The Trade Desk, Amazon DSP, and Basis today, with additional DSP and retail-media-network partners on our roadmap. This team is a central piece of Fluency's strategic position as a gateway through which agents, brands, and agencies reach the full paid media ecosystem. The Fluency platform is built using a native AWS architecture , leveraging Java , Spring Boot , RDS/MySQL , S3 , and Vue.js . Job Summary The Principal Software Engineer, DSP Integrations is a full-time remote role with an optional office in Burlington, VT. This is a senior individual contributor role focused on the architecture and execution of Fluency's integrations with major Demand-Side Platforms, with a near-term focus on accelerating Amazon DSP delivery and sustaining cross-DSP integration depth across TTD, Amazon DSP, and Basis. The DSP Integrations team does not build a DSP. We build the integration layer between Fluency's automation platform and the DSPs our customers use. As the Principal Engineer on this team, you will be the senior technical voice on integration architecture, partner API design, and the encoding of each DSP's distinctive operational semantics into Fluency's platform. You will work alongside the team's tech lead and engineers, contributing architectural depth and hands-on execution rather than people leadership. Your Role Architect Fluency's integrations with major Demand-Side Platforms (currently TTD, Amazon DSP, and Basis; expanding over time). Design and own partner API integrations (REST and GraphQL), including authentication, rate limits, retries, idempotency, reporting feeds, and webhook patterns. Encode platform-specific operational semantics (campaign and ad group structure, targeting, budget behavior, bid strategies, attribution windows, learning-phase triggers) so that Fluency executes correctly on each DSP. Implement cross-DSP capabilities including blueprint integration, reverse sync and forward mutate patterns, and object authority models. Partner with DSPs at the engineering level , collaborating with partner-side technical contacts to unblock integration work. Set technical direction and quality standards through architectural decisions, code, and design reviews, exercising influence rather than formal authority. Triage and resolve partner-integration defects and client-launch issues affecting campaign execution and reporting accuracy. What We Look For Core Experience 8+ years of software development experience, with a heavy focus on backend architecture and integration design. Direct experience integrating with major DSPs as a consumer of their APIs (TTD, Amazon DSP, Basis, MSFT DSP, Yahoo DSP, StackAdapt, or equivalents). Hands-on knowledge of more than one is strongly preferred. Deep experience working with partner APIs at scale : REST and GraphQL, authentication patterns, rate limits, retries, idempotency, reporting ingestion, and webhook handling. Practical understanding of DSP operational differences (budgeting, pacing, targeting, bid strategies, reporting), with a track record of encoding those differences correctly in integration logic. Proven proficiency with Java and Spring Boot , including event-driven services (e.g., Kafka). Knowledge of cloud infrastructure (AWS) and experience with distributed systems operating at high data volume. Capability areas that matter most Distributed systems at walled-garden API volume. You have built high-throughput orchestration on top of partner APIs, with resilience under platform-side instability, and have the discipline to encode platform operational knowledge as structured, testable, continuously-updated capability. AI-augmented production pipelines. You have built production systems where LLMs, deterministic rules, machine learning models, and purpose-built inference coexist, with work routed to the right layer based on cost, latency, and correctness. AI-augmented software development. You operate well in an AI-augmented engineering workflow: strong at specification, review, architectural decomposition, and judgment under ambiguity, and able to work productively at higher levels of abstraction. Other qualities we look for Comfort with high-volume integration workloads. Fluency operates at $3B+ annualized spend across 250,000+ monthly campaigns. Strong bias toward ownership and impact in an environment with aggressive deadlines and externally committed delivery dates. Passion for iterative development and continuous learning. Fluency is headquartered in Vermont. This position is remote US based. If local, you have the option to go into the office. Fluency pays all employees based on U.S. nationwide averages for each role, designed to ensure pay equity. This is a full-time, remote position that requires legal authorization to work in the U.S. Starting pay range is $160,000–$184,000 and is determined by job-related skills, experience, and knowledge. The role is also eligible for a discretionary bonus, equity options, and a comprehensive benefits package including; Medical, dental and vision coverage for employees and their families 401(k) plan with company match Four weeks of Combined Time Off (CTO), flexible schedule and and twelve holidays Maternity and parental leave Employee wellness programs and mental health support Remote work flexibility and home office stipends At Fluency, we’re proud to be an equal opportunity employer. We’re committed to building a diverse, inclusive, and supportive workplace where everyone can thrive. We welcome applicants of all backgrounds and identities and do not tolerate discrimination or harassment of any kind. Employment decisions at Fluency are made based on business needs, job requirements, and individual qualifications—without regard to race, color, religion, sex, sexual orientation, gender identity or expression, age, national origin, disability, genetic information, veteran status, or any other status protected by federal, state, or local laws.