Moodsonic uses sound to improve how indoor spaces feel. Our platform delivers adaptive soundscapes for workplaces, hospitals, universities, and other shared environments shaping daily life, integrating with hardware, building systems, and an array of applications to respond dynamically to activity levels, time of day, environmental sensors, and user input. The work sits at the intersection of audio, real-time systems, and human experience.
The role
We are hiring a Senior Software Engineer to own the backend that the entire product stack sits on: services, data layer, identity and authentication infrastructure, partner-facing integration APIs, device communication, and the security posture. You will own, evolve, and build the systems that power our internal tooling, customer-facing applications, partner integrations, and hardware deployments, strengthening what is already in production and shipping what comes next. You will be the technical lead on production engineering, security, and code quality, building on the foundations the team has put in place. As Moodsonic scales, you will keep the platform safe, reliable, and defensible. You are joining a team where colleagues hold deep domain knowledge. You will need to build trust, collaborate well, and lead through influence rather than authority. This is not a management role. The platform is live and growing quickly, with real customers and real consequences.
What you'll work on
In your first six to twelve months:
- Own and evolve the backend platform: services, data layer, infrastructure, APIs. Strengthen what is in production today, design what is missing, and build what comes next
- Own the backend side of how our deployed hardware connects to the platform: ingestion, device authentication, fleet management, and remote provisioning. Visibility and input into on-device code decisions, because device security is platform security
- Own the identity, authentication, and account layer of the platform
- Own and operate our data protection posture across the platform: encryption in transit and at rest, key management, data lifecycle, and recovery
- Own the partner-facing integration APIs end to end, from design through operation. These are the surfaces our customers and hardware partners build against, and their reliability is our reputation
- Own the engineering practices that support our certifications and audit-readiness
- Establish and maintain the engineering standards (testing, review, deployment, monitoring, secure coding) that the team operates by
- Partner with the engineers owning the audio engine and frontend surface on the backend contracts their work depends on
What we are looking for
Required:
- 5+ years shipping and operating production backend systems, including time on-call and in incident response. You know what it feels like when something breaks at 2am and you own the fix
- Operational resilience as a habit: you design for failure, build with recovery in mind, and treat incident learning as a driver of engineering quality
- Strong judgment in small-team environments. You have owned quality yourself rather than inheriting it from process. You can take high-level product, customer, or security needs and turn them into practical technical plans without a big PM or architecture layer handing you a spec
- Deep relational data modeling and schema design. Postgres or equivalent as a daily tool. Strong instincts for migrations, indexing, and query performance under load
- API design experience: you have built and maintained APIs that outlived their first version and you have opinions about versioning, compatibility, and contract discipline
- Identity and authentication systems experience: modern identity protocols (OAuth or similar), session management, role-based access, multi-tenant boundaries. You understand what breaks when these are wrong
- Security mindset in practice, not theory. You think about attack surface, threat models, and access control as a matter of course, with working knowledge of cryptography and data protection fundamentals
- Code quality and observability as habits. Tests, substantive review, documentation, and the instinct to measure how software behaves in production are part of doing the work, not chores after it
- Strong Python for backend services. Comfortable with SQL, Docker, at least one major cloud, infrastructure as code (Terraform, Pulumi, or equivalent), and modern CI/CD practices
- Modern AI development tools are part of how you ship. You stay current as they evolve, adopt what adds value, and use AI to go faster on work you already understand, which is why you catch AI mistakes before they become bugs
- Demonstrated technical leadership through influence, not authority: you raise the bar through code review, standards, and example, and you have earned trust from engineers who were there before you
- Pride in craft, proactive risk-flagging, and the instinct to raise quality bars rather than work around them. Intellectual honesty and the willingness to push back when the right answer is unpopular
- Clear written and verbal communication, particularly when working asynchronously across time zones
Valued:
- Designing systems that interface with deployed hardware: device fleets, provisioning flows, secure OTA updates, telemetry ingestion
- Shipping to enterprise customers, incident response commitments, and contractual security obligations
- Experience inside a compliance-driven environment (SOC 2, ISO 27001, HIPAA, or equivalent) or building for auditability as a default
- Kubernetes and modern container orchestration
- Additional backend language fluency (Node or TypeScript, Go, Rust) for polyglot service work
- Audio, signal processing, or real-time systems background
- AI and machine learning in product contexts: audio generation, personalization engines, training and serving pipelines
Not required but welcome:
- Interest in sound, music, acoustics, or the wellbeing applications of audio
Team and how we work
You will join a small, senior team distributed across the UK, Europe, and the US West Coast. We run a weekly product cadence, work asynchronously by default, and rely on clear written communication to stay aligned across time zones.
Compensation and benefits
Base salary £65,000 to £85,000, calibrated to experience. Equity will be a material part of the package. Benefits include private medical insurance for UK employees, 28 days paid holiday inclusive of UK holidays, flexible remote-first working. UK right to work is required.
How to apply
Send a short note, your CV, and links to work you are proud of. Please include three to five sentences on a production system, API, identity/auth, or platform hardening project you owned.