Senior Software Engineer - Frontend Developer Experience

As long as there have been buildings, there has been scaffolding. In the caves of Lascaux, sockets in the cave wall were used to build scaffolds, allowing its Paleolithic inhabitants to craft their majestic cave-paintings, which survive to the modern day. From that time onward, every edifice has had its scaffold— from the bamboo poles that held the craftsmen of the Great Wall of China, to the steel trusses that held aloft the ironworkers who raised the Empire State Building. Mercury is growing rapidly. As our product expands, we’re evolving the frontend foundations that support it. We have strong scaffolding in place today, but the expansion, renovation, and exploration that come next will require us to strengthen and refine it. We’re looking for an engineer to help build the battens and transoms that lift frontend work at Mercury. To put it differently, our job is to make our engineers as excited about the frontend as our customers are about our product. As part of this role, you will: Strengthen the frontend foundations every Mercury engineer builds on. Evolve our React, TypeScript, and Vite infrastructure to support teams in shipping ambitious product work with speed and confidence. Help engineers move efficiently with automation. Use static analysis, local tools, and LLM coding tools to help engineers quickly resolve the schlep so they can focus on what matters. Optimize our testing platform for fast feedback loops and high confidence. From unit tests to visual snapshots, you’ll provide the QA tools product teams need to move both quickly and safely. Make our CI/CD pipelines stable, ergonomic, and fast. Mercury ships fast— dozens of deploys to prod per day, and hundreds more commits on PR branches. You’ll keep the pipeline humming so Mercury’s engineers stay in flow and customers see fixes faster. Make our systems and organization observable. Drive decisions by unifying t