Senior Software Engineer (Elixir)

Running a frontline business is an operational puzzle most software has never touched. Shift-by-shift labour costs, compliance that changes by region and by role, and margins thin enough that a badly built rota can sink a quarter. It's a harder problem than most white-collar SaaS, and yet frontline sectors employ 80% of the global workforce and have received about 1% of the last decade's software investment.

We think that's because the problem needed AI, not just better software, before it was solvable. Frontline organisations sit on enormous amounts of operational data. Used properly, that data lets agents take on real parts of running the business rather than just reporting on it. That's what we're building at Sona, and it's early enough that the systems you build now will still be foundational in three years.

We've raised over $100M from N47, Felicis, Gradient and Northzone, signed more than 100 enterprise customers across the UK and US, and opened offices in London, New York, Austin and Lisbon. More on working at Sona here .

About the Role

We're hiring Senior Software Engineers to join our product teams and help build the next generation of workforce management. This isn't a traditional engineering role - at Sona, engineers are deeply embedded in the product development process, working directly with customers to understand their pain points and turning those insights into shipped solutions. AI tooling is central to how we work.

Coding agents produce the majority of our code, and your job is to direct, correct, and architect - not type every line yourself. You'll use tools like Claude Code, Cursor, or similar as a core part of your daily workflow, and we'll assess that proficiency as part of the interview process. To do that well, you need strong Elixir expertise - enough to know when an agent's output is wrong and how to fix it.

Day to day, you'll work within a cross-functional product team with significant autonomy over how to reach outcomes. You'll participate in defining features and scope from PR FAQs and kick-off conversations rather than picking up fully specified tickets. You'll also have the opportunity to rotate across different product domains throughout the year - scheduling, payroll, HR, staff engagement - giving you breadth that most engineering roles don't offer.

This role is remote-first for anyone based in a European timezone, with quarterly in-person team alignment sessions and client workshops in London. It's not a fully isolated remote setup - you'll need flexibility to travel for the moments that matter.

Responsibilities

• Own features end-to-end across Sona's platform, from scoping through to delivery, including in the mobile app Use AI development tooling as your primary workflow - directing and evaluating agent-produced code, not writing everything from scratch Work directly with customers through workshops, feedback sessions, and discovery conversations to ensure what you build solves real problems Collaborate closely with Product Managers and Product Designers to shape solutions from vague requirements and kick-off outputs Contribute to multiple product domains across the year, building deep understanding of workforce management challenges Participate in the product development process - challenging scope, suggesting approaches, and making pragmatic trade-offs between the ideal solution and the right one for now Requirements You're a senior engineer who's comfortable owning features from scoping to production - not just executing against a spec You have professional Elixir experience - enough to evaluate and correct agent-produced code in a production codebase AI development tooling is already embedded in how you work, not something you've experimented with once or twice.
• You can articulate your workflows and demonstrate them under pressure You care about understanding customer problems as much as solving technical ones, and you're comfortable being in front of customers directly You communicate clearly and concisely - adapting for technical and non-technical audiences alike You're pragmatic: you can let go of a strongly held opinion when the situation calls for it, and you make trade-offs consciously Bonus: full-stack experience including React Native, background at a product-led engineering team or high-growth B2B SaaS company, or familiarity with HR/workforce management domains Benefits Salary: £85-105k Remote-first (Europe timezone) with quarterly in-person sessions and client workshops in London Share options 35 days annual leave (25 days standard plus 10 flexible public holiday days) Extra day of leave for every year of service Pension contributions matched up to 5% Comprehensive health insurance Enhanced parental leave & pay Salary sacrifice childcare scheme (Workplace Nursery) Co-working space stipend for those based outside London Annual all expenses paid team retreats The latest Macbook and equipment budget for your home office Professional development budget Unlimited