Software Engineer - Mercury Command

About this role

In 1965, an engineer in Scotland was given a mundane task with a tricky problem to it - banks wanted to close on Saturdays and still serve customers, but they didn’t know how to solve authentication of the right user. James Goodfellow, working at Smiths Industries, uncovered the insight that you needed something you have (a card) and something you know (a PIN). Because someone told him they could only remember 4 digits instead of his proposed 6, today over 3 million ATMs use a card+4 digit PIN over 60 years later.

Like the ATM, Mercury is building technology that pushes forward financial interfaces for the long term. Command is Mercury's LLM-powered financial assistant, launched to all customers in June 2026. It lets users understand their finances and take action in plain language, from asking about cash flow to sending payments, issuing cards, and managing invoices. With the product now in customers' hands, the work is to evolve it, extend its capabilities, and find new ways to leverage LLMs to give Mercury customers a more powerful banking* experience.

What You'll Do: Ship new capabilities users love Feel a strong sense of product ownership and actively seek responsibility – help design and ship new Command skills Partner with product and compliance teams to define what "working correctly" means for each new capability, then build the tests that prove it Join a small but mighty team of experienced product and AI engineers building the future of Mercury This list is illustrative.

Command is a product in motion and priorities will shift as we learn. The right person should be comfortable working in ambiguity, in a scrappy startup environment The Ideal Candidate: Has 1-4 years of backend or full-stack development experience, with knowledge of or excitement to learn Haskell, React, TypeScript, and Redux Experience building LLM powered products A builder who is passionately product-minded and has experience building and shipping new products Empathizes with users and can channel their perspective to build lovable products Can balance tradeoffs and find creative solutions to accomplish goals Actively incorporates AI tools into their workflow and is excited about leveraging them to amplify their impact — whether that's accelerating development, improving code quality, or finding creative solutions to hard problems If this role interests you, we invite you to explore our public demo at demo.mercury.com .