• Own end-to-end delivery of significant backend platform components, taking work from design through production within an established architectural direction • Lead implementation in a focused domain such as integrations, messaging infrastructure, data ingestion, or one of the core platform services • Make day-to-day technical decisions within your domain on data modeling, API design, error handling, and operational concerns, partnering with the Staff Engineer and tech leads on broader architectural calls • Partner closely with AI Engineering and Product to translate evolving requirements into reliable, well-tested software • Drive reliability, performance, and observability improvements in the systems you own; respond to production issues and lead the fix • Mentor mid-level and junior engineers on your team through code review, pairing, and design feedback; raise the bar on engineering craft within the team • Contribute to platform-wide design discussions and influence the standards you operate under

Role Description At Numero, we build software for political campaigns and nonprofits. Since our founding in 2019, we’ve scaled our platform to serve thousands of campaigns ranging from city council seats to US Senate races, and have helped them collectively raise over $10B in contributions. We’ve experienced tremendous growth over the past several years and are hiring experienced engineers to help us scale our backend infrastructure and to support the development of several new products on our roadmap. In joining our team of 6, you will help shape our team’s culture and have a substantial impact on the success of our company. The work at Numero is challenging due to the nature of what we build. We're looking for someone who finds that kind of nuance and scale genuinely fun to untangle – and who has the experience to do it well. Qualifications - Deep experience building and scaling user-facing backend systems (ideally 6+ years). - A deep, instinctive understanding of how code behaves at scale. - Real fluency with SQL and relational data at scale. - A bias toward building things the right way. - Hands-on experience building with AI – and a hunger to get sharper at it. - Excellent written and verbal communication and high EQ. - Located in the continental USA (ET, CT, MT, PT) and willing to travel 1-2x a year for company retreats and/or team offsites. Requirements - Experience with AI tools in day-to-day engineering. - Ability to analyze performance metrics and monitoring after shipping. - Experience with building patterns that scale well. Benefits - Flexible PTO (including 12 company holidays and 2 weeks of required PTO each year). - 401K Plan with employer match. - Medical, dental and vision coverage with HSA option; 50% coverage for dependents. - Paid Parental Leave for primary and secondary caregivers. - Your choice of premium tech setup – laptop, monitor, accessories, and headphones. - $1,000 for your work-from-home setup. - Annual company retreat and/or team offsites. - Professional development support – investment in courses, certifications, or training. Company Description Our founding team is comprised of Brian (CEO), Karan (CTO), and Susie (CFO). We have experience founding startups, leading engineering teams, and managing multibillion dollar budgets at Fortune 100 companies. We are here because we love it and know that this is some of the most important work we could put out into the world.

• Serve as Legion’s senior-most hands-on technical authority for complex architecture, system design, and platform evolution. • Personally dive into code, design documents, production incidents, performance bottlenecks, and implementation tradeoffs to diagnose root causes and guide technical direction. • Lead the hardest technical decisions across AI systems, optimization engines, distributed systems, data architecture, reliability, scalability, security, and platform modernization. • Write prototypes, reference implementations, architecture decision records, technical specifications, and design patterns where needed to unblock teams and establish clear direction. • Make high-consequence technical decisions with incomplete information, balancing correctness, simplicity, speed, scalability, reliability, cost, and long-term maintainability. • Challenge architectural drift, unnecessary complexity, weak abstractions, and short-term decisions that create long-term platform risk. • Partner directly with Staff, Principal, and senior engineering leaders in design reviews, code-level discussions, and implementation planning. • Define and own the long-term architecture for Legion’s AI-driven Workforce Management platform across application services, data infrastructure, ML systems, optimization engines, APIs, integration architecture, developer platforms, and enterprise-scale operations. • Establish engineering-wide standards for system design, scalability, performance, reliability, extensibility, observability, security, and maintainability. • Ensure Legion’s architecture supports enterprise configurability and extensibility without allowing uncontrolled customization or product fragmentation.

• Desarrollar nuevas características y mejoras para nuestros productos y servicios de manera segura y bien probada, siguiendo las pautas de la empresa. • Escribir documentación técnica detallada. • Resolver problemas técnicos de alcance y complejidad moderados. • Garantizar el estilo de código, la mantenibilidad y las mejores prácticas. • Brindar mentoría a los Ingenieros Junior en tu equipo para ayudarlos a desarrollar sus habilidades técnicas y eliminar obstáculos para su autonomía. • Lanzar con confianza características y mejoras de tamaño moderado con orientación mínima y apoyo de otros miembros del equipo.