Member of Technical Staff - Engineering Lead, Applications in London

Our Mission Reflection is a research lab making intelligence open and accessible for everyone to use, customize, and build on. We build open models that let anyone control their intelligence and help shape the future of AI. Our mission: make intelligence open and accessible to all.

ABOUT THE ROLE Reflection's Applications team builds the product surfaces that turn raw platform capabilities into usable workflows — the internal dashboards, admin tools, and self-serve experiences our teams run on, and the customer-facing surfaces that connect Reflection to the outside world. This work sits at the intersection of engineering and product: translating ambiguous requirements into clean, operable systems and taking ideas from prototype to hardened production.

As Applications Lead, you'll provide front-line leadership of the team that builds these surfaces. You'll build, mentor, and grow a team of full-stack engineers, guide the technical and architectural decisions that shape what we ship, and work closely with research, platform, and product to decide what gets built and how. You'll stay close enough to the stack — UI through API through auth — to make targeted contributions as an individual contributor and to maintain a deep understanding of the team's technical work.

WHAT YOU'LL DO

• Build, mentor, and grow a high-performing team of full-stack engineers. Coach and support your reports in understanding, and pursuing, their professional growth.
• Provide front-line leadership of engineering efforts to build internal and customer-facing product surfaces dashboards, admin tools, and self-serve workflows.
• Stay hands-on: become familiar with the team's technical stack enough to make targeted contributions as an individual contributor.
• Manage day-to-day execution: prioritize the team's work and manage projects in a highly dynamic, fast-paced environment.
• Guide technical and architectural decisions, emphasizing scalability, robustness, and user experience across React/TypeScript front ends, REST/gRPC APIs, Go/FastAPI services, and the auth, RBAC, and audit underneath.
• Work closely with research, platform, and product to translate needs into clear system designs and usable interfaces, and to make integrations with customer environments reliable and maintainable.
• Raise the bar for technical judgment, prioritization, communication, and execution in a fast-moving environment.

WHAT WE'RE LOOKING FOR

• Experience building, mentoring, and growing engineering teams while staying technically hands-on. (Comfortable growing into leading a team of ~10 quickly if you haven't managed at that scale before.)
• Deep full-stack engineering experience, with real ownership of production-grade applications shipped end to end.
• Strong coding ability and the credibility to earn the technical trust of a strong team.
• Comfortable across the full delivery surface — UI through API through auth — with depth in at least one layer and the ability to work across the rest.
• Experience integrating with external systems or customer environments and making those integrations reliable and maintainable.
• Ability to guide strategy and drive execution in a fast-moving, zero-to-one environment, and to partner effectively across research, platform, and product.

What We Offer: We believe that to make intelligence open and accessible to all, you need to start at the foundation. Joining Reflection means building from the ground up as part of a talent-dense team. You will help define our future as a company, and help define the future of open foundational models. We want you to do the most impactful work of your career with the confidence that you and the people you care about most are supported.

• Top-tier compensation: Salary and equity structured to recognize and retain our talent globally.
• Stock options: Everyone who joins and contributes to Reflection's success gets to share in the upside through stock options.
• Health & wellness: Comprehensive medical, dental, vision, and life, with an annual wellness allowance.
• Meals: Lunch and dinner are provided in the office daily.
• Life & family: 22 weeks paid parental leave for all new birthing and non-birthing parents, including adoptive and surrogate journeys.
• Vacation days: Unlimited paid time off in the U.S. and 30 days in the U.K.
• Sponsorship support: We sponsor visas to help exceptional talent join our team and support long-term immigration pathways where applicable.
• Team building: We have regular off-sites, happy hours, and team celebrations.

Export Control Notice: This position may require access to technology or source code subject to the U.S. Export Administration Regulations. Any offer of employment for this role may be conditioned on the Company's ability to provide the candidate with access to such technology or source code in compliance with applicable U.S. export control laws, which may require the Company to seek government authorization.